My 2001 vw beetle glx 1.8t..had PO172.. Cleaned the airflow sensor and throttle body..Runs like brand new now..As a mechanic for 32 years in Audi Bmw Mercedes I recommend cleaning the airflow sensor every oil change..at 2000 miles..Thank You and I approve this message...
Taken on a 175km trip now all looks good (touch wood) STFT around -1.6 Banks 1 and 2 LTFT around -7 Banks 1 and 2 and motor seems to be running smoother. Next I will check Fuel consumption Thanks for your help. Over here in Australia most of the mechanics I have spoken to about this problem just tell me to just reset the codes, this has made my head hurt for o many years, my fingers are crossed. Graeme in OZ
Blackbox is ecu. New stuff to learn for old timer.I ask my kids if I have trouble with my pc. Lol. I wondered how my bike starts without choke, now I know.I have to watch more of your vids. Great stuff.
Mike- we just had a uplander in class with rich codes and intermittent hard start. FFV, alcohol content was reading 75% but actual content in fuel was less then 10%!
That's crazy, nice find Jake!!!!! Chevy seems to have an issue with this. Was this a sensor style or algorithim style alcohol content monitor? Actually in the next class we are going to be talking about measuring that content as part of the diag procedure. Mike Becker, Technical Services Instructor
A little late to the game Mike, but THANK YOU! for the invaluable content. These classes are pure gold when it comes to understanding how these systems work. This is one of those principle concepts that if you can understand you can troubleshoot a lot of issues that we face as techs. I found your channel from Eric over at SMA and I'm sure glad I did. Cheers from Stevens Point.
Hey Jordan, Your welcome from GoTech and thanks for your support! You are 100% correct! understanding principles and concepts is the key to diagnostics. Keep up the good work! ~Ryan Wilsing
Wisconsin!!!! ...and thank you for actually being well educated. So much bad info out there. ...people who think that O2 sensors measure fuel and not oxygen. The moment you said that a rich mixture could cause a misfire, which would actually create a lean reading from the O2 sensor, I knew that you actually knew what you were talking about.
@@GoTechTraining actually was kinda losing my mind about an O2 sensor on my 1999 Saturn SL2. Had a head gasket go recently because back when I rebuilt the engine, I used bad head bolt instruction from a Haynes manual. Managed to get 140,000 miles out of the gasket using original head bolts, but it finally failed, and kinda contaminated the O2 sensor. New bolts, new gasket, proper tightening sequence, new fuel filter at 358,000 miles (3rd one for this car), and new O2 sensor, and whenever I took the car over 70 or floored it, the readings would max and then drop to zero. Thought too much fuel or too little fuel, but the pressure holds constant on the original pump, and trims are otherwise in range. Put back in the old sensor, and it started doing the same thing. At this point I'm thinking wiring or computer, and the old one did it worse at any freeway speeds. It was terrible. Made the car run super rich because the computer started adding fuel when it dropped to zero. (Also checked plug gaps, wire resistance, and coil resistance at 70°F.) Finally grabbed an old sensor I had lying around that I pulled long ago for slow response, and it works at all speeds and loads! So they were just overheating and shorting. Have another on order. Hope it won't be defective.
Also for the vehicle to be running rich, you could be getting blow by and the air gathering up oil and taking it through a failed crank case vent or pcv into the intake whereby it would be burnt and making the exhaust rich.
Hey James, you're absolutely correct. Oil could end up in the intake manifold and cause the engine to run right. Nice! Mike Becker, Technical Services Instructor
I have this problem since two months now, which literally drives me crazy! About the symptoms: Very noticeable jerking, stuttering and starting difficulties when the engine is warm/hot. Sometimes the engine won't even start at all. Engine has starting-problems. The problem only occurs after the engine has warmed up and ONLY when starting/idling. Error only occurs after about 10-15 minutes after the car has been shut down. ISTA says P0172: system too rich; which means that the DME either detects too little air or too much gasoline. So to reproduce the problem: 1. Car start perfectly when cold, not a single problem or vibration! 2. I drive half an hour normally (City/motorway) 3. Shutting the car off. 4. Waiting 15 - 20 minutes 5. Restarting the engine 6. Either the car starts with huge difficulties (sputters, shakes, jerks) OR it stalls and shuts off immediately. So far I've replaced: Intake manifold gaskets. (Even though this can't be the cause of the issue, since in the event of an air leak the DME would detect too much air and not too little (or am I wrong there?) 6x injectors 6x spark plugs 6x ignition coils MAF 2 O2-sensors 2 MAP sensors Air Filter Engine oil change (with filter) 2 Camshaft Positioning sensors Cleaned both Vanos-Selenoid Crankshaft Positioning sensor I'm struggling to understand why an intake leak would cause a rich mixture?!ISTA says I have to check the Intake system... (I already checked 3 times!, although without a smoke-tester) Wouldn't an air leak cause a lean condition since unmeasured air enters the engine? OR The ECU demands more fuel because there's an intake leak. In other words; since there is unexpectedly more air in the system, the DME has to spray more fuel to compensate the unmeasured air; hence "system too rich"? Therefore the ECU recognised that more fuel is sprayed into the engine as usual and because of this the DME says: system too rich? ----------------------------------- Intake leak = More (unmeasured) air requires more fuel to be sprayed into the engine to compensate the "unknown" air, therefore "system too rich" --> Because the DME has to put more fuel then normal? OR Intake leak = More (unmeasured) air requires more fuel to be sprayed into the engine to compensate the "unknown" air, therefore "system too lean"? --> Because there is more air then normal? Am I losing the plot here? Both make sense, but which one is scientifically and physically right? I'm desperate and on the verge of a mental breakdown
@@GoTechTraining Please I really need your help. Nobody is able to help me. Not even the dealership It seems like gas is getting into the oil pan. I changed the oil, and it ran fine for 3 days. Then stalling issues again. Have you had a chance to think about it? Or do you offer something like a TeamViewer function? Thank you
Juergen, yes you're right. It is in frames not seconds, I misspoke. Sorry about that! Thanks for correcting it! Mike Becker, Technical Services Instructor
P0171 basically means you have a vacuum leak usually the first place I go to the gas cap to make sure it was tightened properly because if it is not then you're going to show a vacuum leak.
Hey David, thanks for watching. So a vacuum leak can set a P0171 but there's also a ton of other things. Also, the gas cap is more likely to set an EVAP code like P0440 or something before setting a lean code. Mike Becker, Senior Instructor
Graeme in OZ UPDATE !!!!!!!!! This weekend may have found my issue, while checking PCV valve I noticed there was a small rubber pipe connected to the valve cover then led to PCV valve the push on connection was very easy to pull apart so I installed small hose clamp to secure it. I then connected my newly acquired Foxwell NT301 OBD2 Engine Fault Code Reader Scanner and found the instrument gave me a green tick indication when connected where as before it was an orange triangle (Yellow indicates there's an issue that has been solved). The Short Term Fuel Trim readings now look better showing around -2 banks 1 & 2 LTFT is about -9 but from what I've read this takes time to adjust after problem is resolved. Will need to take her for a few drives to see if I have solved the 13 Year issue !!!!!!!!. Graeme in OZ
Hey Graeme, that's awesome!!!! Yeh, LTFT will take a little time to come back to normal. Sounds like you just might have it fixed :) Mike Becker, Senior Technical Instructor
Hey Mike, I'm 52 years old and knows nothing about the tech side of a car...been watching your videos, if I don't understand I'll rewind for second and third viewing, but I'm learning so much from you. Just brought a scanner (Autel MOT Pro, is this good scanner?) and playing with it and understanding it more because of your teachings....you are doing a great job, minus the cough. If I could give you 10 thumbs up I would.
Hey John, yeh i was a little bit sick in this video. Glad we are helping you learn. Means a lot to us! That's a good starter tool. Get's you some codes, and some info. There will always be room to grow in tools if you really get into this. Thanks for watching! Mike Becker, Technical Services Instructor
I am here after following Eric O's link from SouthMain Auto's. He is right you people are the experts. A brilliant lecture, I am looiking forware to watching your etire portfolio thumbs up and subsribed. THANK YOU ****************
Well done good vid again on the page where you showed 450 MV rich and lean this is only on narrow band 02 sensor (nothing on the page about wide band ) I struggle with wide band still learning .great vid guys loving it 👍👍👍
Scott, you're in luck! We are going to be getting into both narrow (O2) sensors and wideband sensors in the next class. I hope next class I can fill you with all the knowledge you ever wanted on widebands! Mike Becker-Technical Services Instructor
Scott, I like that, the tomato sensor. Stay tuned my friend, next class is February 2nd at 11am and 2pm central time. Hope to see you there! MIke Becker, Technical Services Instructor
thank you for this video , excellent information . I've been wrenching since the 80's and I still love to learn about how cars work and this is a fascinating time to be a tech with all the changes happening year to year . I also didn't see the need for parts to be shown .
Hey John, thanks! It really is an amazing time to be in the automotive industry. So much to learn, it's evolving soooo quickly! Mike Becker, Senior Technical Services Instructor
Hey Mike is good teaching me alot and it my first time watching your video.. but I can't wait to see electronics problem. Cause im not good a lil bit electronic repair or something
Hi Gerardo, thank you! I hope these videos can really help you get better at electrical and diagnostic problems! Thanks for watching. Mike Becker, Technical Services Instructor
I had a throttle body relearn done to fix the constant problem after cleaning it. I think I may have made a mistake I did a fuel composition reset using X431 on my 2011 5.3 flex fuel suburban , currently have e85 in my tank. Now I have 2 code errors p0171-00 and p0174-00 fuel trim lean system lean bank 1 and 2. Did I do something wrong? I would appreciate any help what to do and proceed. Thank you
Hi Ken, Your vehicle uses an algorithm to calculate fuel ethanol %. When you reset the fuel composition, it defaults to >10% ethanol. Since E85 burns at closer to a 10:1 ratio compared to Gasoline at 14.7:1 it will cause your vehicle to run lean and set those codes. The only way to fix this issue without measuring the ethanol content and re-programing the ECM. Is to run the tank empty and put in a tank of regular 10% or less ethanol in and do the fuel composition reset again. This way the ECM learned percentage will match the fuel in the tank. Unless you manually drain the tank, you may have to do this twice to get the % back to normal. Hope this helps, Thanks Ryan W, Technical Instructor
Very good video with a lot of helpful information . Thank you. Quick question, My car recently was running lean 21 percent lean long trim and 18 short trim on bank 2 due to a exhaust leak between the 2 flanges right before the cat. I got that fixed and now the car sometimes runs -18 but mostly stays on -6 to -12 range on short trim and bounces from -10 to 3 on long trim. How many driving cycles does it take for it to adjust to normal .So far I drove the car 3 times
I've have learn a lot from watching this video thanks guys Just one question. My car was running lean on bank 2 due to a vacuum leak. 21 short term and 16 long term during idle Well I got that fixed and now its running rich each time I accelerate. Like sometimes 8- to 13- on the long trim and 5 to 8- on short trim. The fuel trims are okay during idle Is there anything I missed? or is it normal for the car to run very rich while accelerating it.
Wouldn't a vacuum leak affect both banks on a two bank engine excluding a Manifold leak on on one bank? Same on a bad injection or bad plug or coil pack on that bank?
to anyone watching this in the future and notices the audio is off, a way to get around this is 2 have two youtube tabs open of this video, one to watch on mute, and another to have audio playing and minimized. the time difference is ~9:40 seconds. so fast forward one to that time mark and then hit play on both of them as quickly as you can. was driving me crazy.
Hello I hope you're doing well just would like to have an idea why the hose that goes from the canister purge valve in the Gasquet it would shrink when accelerating i would really appreciate it thanks
Long Term is the window of time the adaptive memory dictates the fuel trim, Short Term is live data calculating to learn the parameters for the adaptive memory to update the Long Term. The O2 sensor signals lean below .45 volts & rich above .45. The Engine Controller only cares about that threshold & uses that to determine fuel trim. .. in other words the computer calculates the % of time that the O2 sensor is past the threshold of .45 volts & does that each time the threshold is crossed.
hi, i,m new subscriber, great video! my car is nissan skyline 300gt 2002 year. lambda is 1,017, but CO is very high 1,57-1,76. what is possible causes? thanks!
Hello. 2003 Mitsubishi 3.8L V-6, 220,000 trouble free miles. Fuel economy is where it should be. LTFT 1&2 are +12.5% at hot idle. But goes to 0% and stays there when revved to 2,500 rpm. STFT 1&2 are 0% at hot idle. When extra fuel is sprayed on identified leak of intake manifold (leaking o-ring, I used smoke to find) the STFT immediately goes to -6 and then returns when the extra fuel is burned off. Could this intake air leak thats affecting both banks cause the truck to go into a limp mode, giving me these codes? P0335 P2135 P0340 Also, why does LTFT go to 0% when under load? Thanks!
HI, The intake leak will not effect cam and crank signals or cause the vehicle to go into limp mode. There must be another issue with the system. With a intake leak fuel trims go down under load for a few reasons. First under load the engine consumes a much larger volume of air, so the air leak affects the fuel trims much less. Also when the engine is at 2500 RPM the throttle body is open causing the pressure in the intake to be close to atmospheric pressure, which means no vacuum in the Intake. With no vacuum in the intake it will not be able to suck as much unmetered air into the engine. Ryan Wilsing, Technical Instructor
@@GoTechTraining thank you very much! That makes sense about the LTFT. I will check out the throttle position sensor as it seems to go back to normal when it cools down for 15+ minutes. Maybe it is overheating. Maybe I can replicate issue by getting TPS hotter with a hair dryer. Thanks again!
Great vid!! I get this code every winter and only in winter. I have absolutely, no symptoms - pont 08 vibe, purrs like a kitten. Chkd for vac leaks, intake gasket, gas cap and o2 sensor. All good. Thinkin maybe fuel injectors or fuel pressure issues. Giv me yur critique!😩 RM.
Hey Rudy, thanks for watching! The Vibes were SUPER common for intake gaskets to leak only when the engine is cold. Has yours ever been replaced? ~Mike
I just found your site. I am new to this and it is very interesting subject. i just bought a new Altel 808 and it amazing to watch it on live data. I have a 1999 gmc k2500 5.7 I have replaced the injection spider and cleaned the carbon out of the intake. I Have changed the o2 sensors and it is telling me that i have a low heater out put on bank 1 sensor bank 2. I have looked at the wiring and it looks good. any ideas. The A/F is 14.7. o2;s are reading 450. The engine is high mileage, does not use any oil, the compression is 160 to 165. starts good and runs great. Thanks
Is your instruction on air and fuel correct? It appears that you are comparing the air and fuel ratio to volume by showing volumes of water. With as much air as an engine breathes, would I be able to get out of the parking lot before I ran out of gas? Shouldn't I be comparing them by weight? (The answer is yes)
I have a P0171 lean code for a Corolla 2001 with 197k miles. My Long Fuel Trims are 40.1 %. Could that be that i have a clogged fuel injector? I cleanned my MAF sensor, change my O2 sensors, change All Gaskets. Still have the code ON. Any advise would be great...
Hey Randal, you want to verify the heater circuit is getting power and ground. You can confirm it by putting a test light across the heater circuit and see if it lights up when the car is started. ~Mike
I have a 1996 F250 5.8. It only has 116k miles on it and the engine sounded really good until a few weeks ago when I put about 2 year old gas in it. I KNOW THAT WAS STUPID. it was about 10 gallons. The very next day, it was rough starting up but it ran fine once it started, however, the next day, the truck was shaking, started sounding like it was misfiring, and whatever. I didnt siphon out the bad gas, instead I out fresh gas in. The fixes I have done on it thus far are: fuel filter, cleaned injectors, spark plugs and wires, new distributor cap and rotor. and it still isnt running right. I took it to a DIY mechanic who has been a mechanic for probably 50 years and he said it sounds like the lifters. What do you make of it?
Do you think that the gas is a coincidence? I find it hard to believe adding old gas caused it to ruin lifters that were fine before. I don't buy it. I would inspect fuel trims. Maybe your gas had water in it and the truck is running lean to the point of misfiring. Not sure on that lifter idea man. I'd do some testing before jumping to engine work on a truck that sounded good. Mike Becker, Senior Technical Instructor
I didnt think so either. My dad had said he didnt believe old gas would be the culprit, but the water content may have the engine running lean. Thank you so much. Ill take this info and work accordingly. You the man. SUBSCRIBED!
Old gas can cause an engine to run poorly. You could try adding some of that water eliminator to the tank. See if it helps, it shouldn't hurt anything. Thanks for subbing man! Mike Becker, Senior Technical Instructor
Do you have a suggestion for this? My VW Golf TSI 2008 (BLG engine code) has a Fuel System Too Rich error. When the exhaust emissions are measured at idle all is fine, but at 2500 rpm the carbon monoxide is way too high. So the car failed inspection today. The error code is actually not present at the moment. I deleted it months ago and it didn't come back. So I forgot about it until I was reminded about it today due to the failed inspection. The error code was P0172
Hey J Wester, a rich condition is a lack of oxygen in the exhaust. It's interesting that it's only under load and not at idle. I'd take a close look at the air fuel ratio sensor and the 02 sensor. Try forcing the car rich and lean and see if the sensors respond appropriatly. Mike Becker, Senior Instructor
@@GoTechTraining Thank you for your answer. This engine seems to be using an 02 sensor. Initially I was looking for the MAP Sensor. In this engine the sensor is an intake manifold pressure sensor combined with intake air temperature sensor. As I understand the computer uses these two values to calculate the air mass and adjusts the air/fuel mixture
Hey, thanks for the video. Very helpful. My shogun sport v6 has codes P0170 and P0173, both fuel trims. It seems to be running fine except a slight change in idling speed every minute or so (from 1000 to 700ish RPM). The previous owner has changed an o2 sensor (top of cat) but the 'check engine light' is back on. I've unplugged the MAF sensor and the idling speed increases, then goes back to normal once plugged back in. That's all I've done so far. Any ideas appreciated! Bit of a head scratcher 🤔
Hey Mark, Do you have a scan tool that can watch data? I'd like to see what the fuel trims are reading at idle and at a moderate load. There are a lot of possibilities to what could cause this issue. Mike Becker, Senior Technical Instructor
@@GoTechTraining thanks Mike, yes I have the torque light obd2 thing I'll take some screenshots and send them to you if you like? There's 4 sensors per bank, I'll try and get them on the same screen. What's your email?
Question: I have a 2013 F30 BMW 328i. I got codes P0171 and P0172 at the same time. The codes contradict each other. My "start/stop" feature in the car doesn't work anymore. Any idea what the issue is?
Can y'all do some post carb, pre obd2 fuel trim videos PLEASE!? Reading blinking lights sucks! Do u have insight? My issue on a poor random idling 92 Nissan MT KA24E KC XE no CEL per Nissan. I'm sick of it becoming this parts cannon.. still have all original parts on hand.
Was just informed about this site; if you're going to do "teaching"/"explanations " of ratios, many will not know if you're talking about weight or volume.(e.g. is 14.7:1 by weight or volume?). Having been a chemist, UNLESS otherwise stated, it is always by WEIGHT. ON the other hand, if your referring to gases("room" temperature), then by volume. It would be helpful to students to clarify this point.
Fantastic lecture! A connected topic: anybody knows how to deactivate learning procedure on a flex fuelcar (volvo in this case) . Thre is no ethanol content sensor but computer leatns thru the Lambda readings and injection pulse duration ...causing many problems when driving regular fuel. I am tired iwth them so simply would love to deactivate the process but there is no obvious way to do so. I can only reset the content to the default value of 50%. Then the crap learns and sometimes rich 70% with the engine to be floode on a cold start. Ideas?
Thank you very much! That seems crazy that the car would "learn" such a high ethanol count with no ethanol in the fuel..what's it truly learning? Are you sure you don't have something wrong causing it to read so rich? I've seem the algorithms get stuck, GM especially, but after resetting they are usually ok again. Is there maybe a software re-flash for the car or something? Mike Becker, Senior Technical Instructor
@@GoTechTraining I missed your reply! Thanks. There is a counter for ethanol content and each time you fill the tank the learning algorithm is initiated. It learns thru the lambda and injections timing. Therefore if there is something wrong with with fuel to sir ratio it interprets it as alternate fuel percentage in the tank and store ty he ethanol content reading. Next time you want to start in cold conditions it ask long injection time to account for ethanol and the engine is flooded. And I have a bi-directional tool so I am able to reset the content to the default (50% !) value. So yes, apparently there is something wrong but it is do tough to find out with this intelligence involved 😂. Would love to deactivate it first but have no idea how. Thinking about replacing the ECU for similar engine one but not accommodated as the flex fuel.
great class mike I'm staring learning of this new computer systems. I'been working on heavy equipment diesel engines for 20 years and now i want to learn more of this new vehicles.
Very useful information sir thank you Sir I have Chevy suburban 2007 and I'm getting codes p0172 and p0175 system too rich on both banks and ratio is showing short fuel trim at 0 and long fuel trim at -25 what do you suggest me to do first
Thank you for watching A Rahman! On your suburban, these were very common to run into fuel composition calculation issues. There should be a PID on your scanner saying ethanol content. Verify that seems right. if you are running standard pump gas we usually look for 5-10%. Anything higher than that can give you issues. Ethanol requires higher fuel volume which could be exactly why your truck is running rich. Mike Becker, Senior Technical Instructor
Very informative. Thanks for the taking the time. You teach a great class. Your step by step process is unmatched. Thanks for passing the knowledge to us all.
My question about the Lambda reading on a scan tool is , for an example, 1.2 on your lambda chart on your video training, when you read this value on a scan tool , is the computer on your car taking fuel away because the fuel trims rich ? If someone can answer the question I would be thankful!
Hello I own a 2005 Crossfire I have codes Chrysler with code P0172 and P0175 > I have had problems I also code P0239 Air induction blower failed but I hear it running at start up. I am a senior citizen and can't afford to take it to a shop if I could find one my next thing is take it off the rd Most shops do not want to work on this car since it is a Bastard car neither Mercedes or Chrysler or individual shops will not touch this car. It has a Mercedes engine 3.2 Liter V6 . I replaced all injectors and plugs wires and and individual coils the car runs great but as soon as I get close to the emission station it throws the P0172 and P0175. I looked for loose vacume hoses and I found one and I fixed that. My car is due in February and I don't know what I can do get this to pass emission. In a few years the car is exempt emission if I use Historic tags. I don't drive car much but the emissions will not allow me to go through the test for a week. Like I said the car runs great but soon as I get close to emission station it throws codes. I drove it for a week and today it did same thing 3 times in a row I went to the emission station. How frustrating.
Hey KComputers, curious, what are you STFT when the LTFT is -10.3? Are they hovering 0? A -10 trim shows you are running slightly rich. What kind of car is this on? Mike Becker, Senior Technical Instructor
I'm also hearing a puff sounds like a vacuum leak . I sprayed starter fluid but not really good at that. It sounds like it's coming from under the intake is there a gasket on it for a PT Crusier 2005 non turbo are they expensive? Also could a purge Solenoid make a puffing sound if stuck open?
Kathy, check out the fuel trims with a scanner. That should lead you down the right path as to whether you have a vacuum leak or not. Mike Becker, Senior Technical Instructor
I'm experiencing pre detention at half pedal. No high tech tools. No codes "OBD1" or dash lights. I'm debating fuel trim or distributor issue. Would one always get a code with fuel trim?
Depends on the car. Most newer cars will set a fuel trim related code once long term fuel trims exceed +/- 10%. What kind of car is this on? Are you running the proper fuel? Mike Becker, Senior Technical Instructor
Thank you for your reply. I actually got annoyed with the car and pulled the distributor, there was an oil Mark on the 3 leaf clover so it was slightly off. 94 Fleetwood 350 with Optispark. Fixed now. Love your vids. Am curious, code reader on dash "no codes" I was told buying an actual reader would not show anything more than what I can already see. Is fuel trims even on the $5k snap on obd1 readers or is it only obd2?
My 2010 Chevy malibu I have the po172 code engine will nit start the oil has gas in it the MAP sensor checked out ok any ideas that would make bank 1 rich
My 03 F150 Lariat 5.4 keeps giving me a P0401 code and negative trims around -12 to -16. I have replaced EGR valve, DPFE sensor (and hoses), EGR tube, EGR vaccum solenoid, IAC valve, plugs, coils, intake manifold, fuel injectors, and EVAP purge solenoid...
Hey M.Night207, what kind of pressure regulator are we talking about? The old school vacuum diaphragm one? If that's the one, then ya, generally speaking it will be leaking if it fails. Mike Becker, Senior Technical Instructor
I have a 03 dodge ram 1500 4.7 and have bank 1 to Rich replace the injectors and fuel regulator and both 02 sensor's n the map sensor but it still idles rough to where it almost dies the truck doesn't have EGR valve
Hey Floyd, are the injectors good quality or Ebay specials? I've heard of cheapy injectors causing issues. Can you force it lean? Mike Becker, Senior Technical Instructor
I have a 06 VW beetle 2.5l. I have a p0171 code. Did a smoke test and no vacuum leak was detected. Car is running rough on idle and reading short term 25% and long term 20%. I changed the maf back in July and it was running great until now. No maf code or anything when it started to have problems. I was told to replace the 02 sensors. Please help.
![MAF and Wideband O2 Sensor Testing for a P0172 [Rich Condition]](/img/n.gif)
My 2001 vw beetle glx 1.8t..had PO172..
Cleaned the airflow sensor and throttle body..Runs like brand new now..As a mechanic for 32 years in Audi Bmw Mercedes I recommend cleaning the airflow sensor every oil change..at 2000 miles..Thank You and I approve this message...
Thanks for sharing
Taken on a 175km trip now all looks good (touch wood) STFT around -1.6 Banks 1 and 2
LTFT around -7 Banks 1 and 2 and motor seems to be running smoother. Next I will check Fuel consumption Thanks for your help. Over here in Australia most of the mechanics I have spoken to about this problem just tell me to just reset the codes, this has made my head hurt for o many years, my fingers are crossed.
Graeme in OZ
My fingers are crossed for you too, Graeme Redman!
Mike Becker, Senior Technical Instructor
This dude really knows what he's doing!
you are a very good teacher the best on the internet by far the way you explaine things im going to start to watch a lot of your content excellent
Hey Wackey, thanks for watching! I really appreciate the kind words.
~Mike
Gracias maestro. Veo sus videos en español pero en inglés un poco. Gracias nuevamente por su aporte a la enseñanza
Blackbox is ecu. New stuff to learn for old timer.I ask my kids if I have trouble with my pc. Lol. I wondered how my bike starts without choke, now I know.I have to watch more of your vids. Great stuff.
Hey Denis! I'm glad you're catching on and educating yourself! Any questions, don't hesitate.
Mike Becker, Senior Technical Instructor
South Main Auto sent me to see your class, Great program, I need lots of this and will follow more videos.
Awesome John! Thanks!
Mike Becker, Senior Technical Instructor
Mike- we just had a uplander in class with rich codes and intermittent hard start. FFV, alcohol content was reading 75% but actual content in fuel was less then 10%!
That's crazy, nice find Jake!!!!! Chevy seems to have an issue with this. Was this a sensor style or algorithim style alcohol content monitor? Actually in the next class we are going to be talking about measuring that content as part of the diag procedure.
Mike Becker, Technical Services Instructor
Great presentation Mike and looking forward to your lecture on the wide band sensors. Have a good weekend!
Thanks Stuzman! Glad you liked it, see you on the next one!
Mike Becker, Technical Services Instructor
hi from vegas really love the way you explain things on the fuel trim made me look at diag from a whole different view thanks
Very informed video, a lot of doubts have been cleared. Your explanation are terrific.
Thanks for watching Mukesh!
Mike Becker, Senior Instructor
A little late to the game Mike, but THANK YOU! for the invaluable content. These classes are pure gold when it comes to understanding how these systems work. This is one of those principle concepts that if you can understand you can troubleshoot a lot of issues that we face as techs. I found your channel from Eric over at SMA and I'm sure glad I did. Cheers from Stevens Point.
Hey Jordan,
Your welcome from GoTech and thanks for your support!
You are 100% correct! understanding principles and concepts is the key to diagnostics.
Keep up the good work!
~Ryan Wilsing
Thank you so much for taking the time to explain everything!!
Hey J G, thanks for taking the time to watch and comment!
Mike Becker, Senior Technical Instructor
Wisconsin!!!! ...and thank you for actually being well educated. So much bad info out there. ...people who think that O2 sensors measure fuel and not oxygen. The moment you said that a rich mixture could cause a misfire, which would actually create a lean reading from the O2 sensor, I knew that you actually knew what you were talking about.
Hey T D, thanks! You a Wisconsinite as well?
Mike Becker, Senior Instructor
@@GoTechTraining yes! Milwaukee
@@GoTechTraining actually was kinda losing my mind about an O2 sensor on my 1999 Saturn SL2. Had a head gasket go recently because back when I rebuilt the engine, I used bad head bolt instruction from a Haynes manual. Managed to get 140,000 miles out of the gasket using original head bolts, but it finally failed, and kinda contaminated the O2 sensor. New bolts, new gasket, proper tightening sequence, new fuel filter at 358,000 miles (3rd one for this car), and new O2 sensor, and whenever I took the car over 70 or floored it, the readings would max and then drop to zero. Thought too much fuel or too little fuel, but the pressure holds constant on the original pump, and trims are otherwise in range. Put back in the old sensor, and it started doing the same thing. At this point I'm thinking wiring or computer, and the old one did it worse at any freeway speeds. It was terrible. Made the car run super rich because the computer started adding fuel when it dropped to zero. (Also checked plug gaps, wire resistance, and coil resistance at 70°F.) Finally grabbed an old sensor I had lying around that I pulled long ago for slow response, and it works at all speeds and loads! So they were just overheating and shorting. Have another on order. Hope it won't be defective.
Thanks for detailed explanations. I appreciate all work you put into making this video.
Hey PistonShack, thanks for watching! :)
Mike Becker, Senior Instructor
Absolutely Brilliant!!! Thanks for the Detailed Explanation!
Also for the vehicle to be running rich, you could be getting blow by and the air gathering up oil and taking it through a failed crank case vent or pcv into the intake whereby it would be burnt and making the exhaust rich.
Hey James, you're absolutely correct. Oil could end up in the intake manifold and cause the engine to run right. Nice!
Mike Becker, Technical Services Instructor
Better than tele. Keep up the good work. Stft and ltft no longer a mystery. Thanks.
Hey Jesse! Thanks, best part is that it's free unlike cable :) Thanks for watching!
Mike Becker, Technical Services Instructor
I have this problem since two months now, which literally drives me crazy!
About the symptoms:
Very noticeable jerking, stuttering and starting difficulties when the engine is warm/hot. Sometimes the engine won't even start at all. Engine has starting-problems.
The problem only occurs after the engine has warmed up and ONLY when starting/idling.
Error only occurs after about 10-15 minutes after the car has been shut down.
ISTA says P0172: system too rich; which means that the DME either detects too little air or too much gasoline.
So to reproduce the problem:
1. Car start perfectly when cold, not a single problem or vibration!
2. I drive half an hour normally (City/motorway)
3. Shutting the car off.
4. Waiting 15 - 20 minutes
5. Restarting the engine
6. Either the car starts with huge difficulties (sputters, shakes, jerks) OR it stalls and shuts off immediately.
So far I've replaced:
Intake manifold gaskets. (Even though this can't be the cause of the issue, since in the event of an air leak the DME would detect too much air and not too little (or am I wrong there?)
6x injectors
6x spark plugs
6x ignition coils
MAF
2 O2-sensors
2 MAP sensors
Air Filter
Engine oil change (with filter)
2 Camshaft Positioning sensors
Cleaned both Vanos-Selenoid
Crankshaft Positioning sensor
I'm struggling to understand why an intake leak would cause a rich mixture?!ISTA says I have to check the Intake system...
(I already checked 3 times!, although without a smoke-tester)
Wouldn't an air leak cause a lean condition since unmeasured air enters the engine?
OR
The ECU demands more fuel because there's an intake leak. In other words; since there is unexpectedly more air in the system, the DME has to spray more fuel to compensate the unmeasured air; hence "system too rich"? Therefore the ECU recognised that more fuel is sprayed into the engine as usual and because of this the DME says: system too rich?
-----------------------------------
Intake leak = More (unmeasured) air requires more fuel to be sprayed into the engine to compensate the "unknown" air, therefore "system too rich" --> Because the DME has to put more fuel then normal?
OR
Intake leak = More (unmeasured) air requires more fuel to be sprayed into the engine to compensate the "unknown" air, therefore "system too lean"? --> Because there is more air then normal?
Am I losing the plot here? Both make sense, but which one is scientifically and physically right?
I'm desperate and on the verge of a mental breakdown
What kind of car are you working on?
Mike Becker, Senior Instructor
GoTech
2012 BMW F10 535i xDrive 109.000 km. Check my video. I captured the problem
czcams.com/video/lBPZEJDPXTw/video.html
@@GoTechTraining Please I really need your help. Nobody is able to help me. Not even the dealership
It seems like gas is getting into the oil pan.
I changed the oil, and it ran fine for 3 days. Then stalling issues again.
Have you had a chance to think about it?
Or do you offer something like a TeamViewer function?
Thank you
@@Italiano9091 if your gas is mixing with oil it could be the high pressure fuel pump.
Awesome video my 2005 mercedes e320 had a lean code what I fund is missed placed snorkle i clear the code I hope everything is fine now thank you
Awesome, gotta love an easy fix!
Mike Becker, Senior Instructor
Oh my, a God sent gem thank you guys.
Thanks for watching Emmanuel!
Mike Becker, Senior Technical Instructor
At 33.12: it's not 260 seconds but 260 frames on the display of the snap on scanner.
Thanks for your time and effort.
Juergen, yes you're right. It is in frames not seconds, I misspoke. Sorry about that! Thanks for correcting it!
Mike Becker, Technical Services Instructor
Okay after watching the this video training my question was answered! Great training thanks!
great info!! hard to follow with the difference in time between video and audio!!
P0171 basically means you have a vacuum leak usually the first place I go to the gas cap to make sure it was tightened properly because if it is not then you're going to show a vacuum leak.
Hey David, thanks for watching. So a vacuum leak can set a P0171 but there's also a ton of other things. Also, the gas cap is more likely to set an EVAP code like P0440 or something before setting a lean code.
Mike Becker, Senior Instructor
Ummm no , not correct at all
Thank you guy’s for your patience and knowledge, where do I join classes? You guy’s should teach classes online or thrue zoom
Graeme in OZ
UPDATE !!!!!!!!!
This weekend may have found my issue, while checking PCV valve I noticed there was a small rubber pipe connected to the valve cover then led to PCV valve the push on connection was very easy to pull apart so I installed small hose clamp to secure it. I then connected my newly acquired Foxwell NT301 OBD2 Engine Fault Code Reader Scanner and found the instrument gave me a green tick indication when connected where as before it was an orange triangle (Yellow indicates there's an issue that has been solved). The Short Term Fuel Trim readings now look better showing around -2 banks 1 & 2 LTFT is about -9 but from what I've read this takes time to adjust after problem is resolved.
Will need to take her for a few drives to see if I have solved the 13 Year issue !!!!!!!!.
Graeme in OZ
Hey Graeme, that's awesome!!!! Yeh, LTFT will take a little time to come back to normal. Sounds like you just might have it fixed :)
Mike Becker, Senior Technical Instructor
Very good, thanks for explaining the details - your words make great sense
Hey Bob, thanks for watching!
Mike Becker, Senior Instructor
Hey Mike, I'm 52 years old and knows nothing about the tech side of a car...been watching your videos, if I don't understand I'll rewind for second and third viewing, but I'm learning so much from you. Just brought a scanner (Autel MOT Pro, is this good scanner?) and playing with it and understanding it more because of your teachings....you are doing a great job, minus the cough. If I could give you 10 thumbs up I would.
Hey John, yeh i was a little bit sick in this video. Glad we are helping you learn. Means a lot to us! That's a good starter tool. Get's you some codes, and some info. There will always be room to grow in tools if you really get into this. Thanks for watching!
Mike Becker, Technical Services Instructor
So nice to see other guys my kind of age who’s lost when it comes to carbs! I know the basics and I know it’s ‘simple fuel control’ buts for me efi is
Ughhh carbs...hahah!
Mike Becker, Senior Technical Instructor
I am here after following Eric O's link from SouthMain Auto's. He is right you people are the experts. A brilliant lecture, I am looiking forware to watching your etire portfolio thumbs up and subsribed. THANK YOU ****************
Well done good vid again on the page where you showed 450 MV rich and lean this is only on narrow band 02 sensor (nothing on the page about wide band ) I struggle with wide band still learning .great vid guys loving it 👍👍👍
Scott, you're in luck! We are going to be getting into both narrow (O2) sensors and wideband sensors in the next class. I hope next class I can fill you with all the knowledge you ever wanted on widebands!
Mike Becker-Technical Services Instructor
Thanks for the quick re
Thanks for the quick reply look forward to it the tomato sensor ,fruit or veg ,fuel or oxygen ?,after a lot of hours on iATN web site tough subject
Scott, I like that, the tomato sensor. Stay tuned my friend, next class is February 2nd at 11am and 2pm central time. Hope to see you there!
MIke Becker, Technical Services Instructor
Great channel to keep learning. Thank you very much guys.
Hey, thank you very much for watching and commenting!
Mike Becker, Senior Instructor
Thank you very much for the information brother. great job.
Thanks for watching!
Mike Becker, Senior Instructor
Great after 6 years 🇯🇲
thank you for this video , excellent information . I've been wrenching since the 80's and I still love to learn about how cars work and this is a fascinating time to be a tech with all the changes happening year to year . I also didn't see the need for parts to be shown .
Hey John, thanks! It really is an amazing time to be in the automotive industry. So much to learn, it's evolving soooo quickly!
Mike Becker, Senior Technical Services Instructor
Hey Mike is good teaching me alot and it my first time watching your video.. but I can't wait to see electronics problem. Cause im not good a lil bit electronic repair or something
Hi Gerardo, thank you! I hope these videos can really help you get better at electrical and diagnostic problems! Thanks for watching.
Mike Becker, Technical Services Instructor
Such a great teacher...god bless you
Thank u for educating us, I always enjoyed your videos
I'm a new subscriber love what you are doing. Hopefully I can catch up and earn a shirt and thanks for taking the time to share great info.
Hey Jason, welcome to the channel! Hope to see you at the live class in April!
Mike Becker, Senior Instructor
Wonderful class...excellent information. Greatly appreciated ..... Thanks and take care
Hey Charles, thanks! Glad you liked the class!
Mike Becker, Senior Technical Instructor
I had a throttle body relearn done to fix the constant problem after cleaning it. I think I may have made a mistake I did a fuel composition reset using X431 on my 2011 5.3 flex fuel suburban , currently have e85 in my tank. Now I have 2 code errors p0171-00 and p0174-00 fuel trim lean system lean bank 1 and 2. Did I do something wrong? I would appreciate any help what to do and proceed. Thank you
Hi Ken,
Your vehicle uses an algorithm to calculate fuel ethanol %. When you reset the fuel composition, it defaults to >10% ethanol. Since E85 burns at closer to a 10:1 ratio compared to Gasoline at 14.7:1 it will cause your vehicle to run lean and set those codes. The only way to fix this issue without measuring the ethanol content and re-programing the ECM. Is to run the tank empty and put in a tank of regular 10% or less ethanol in and do the fuel composition reset again. This way the ECM learned percentage will match the fuel in the tank. Unless you manually drain the tank, you may have to do this twice to get the % back to normal. Hope this helps, Thanks
Ryan W, Technical Instructor
Very good video with a lot of helpful information . Thank you. Quick question, My car recently was running lean 21 percent lean long trim and 18 short trim on bank 2 due to a exhaust leak between the 2 flanges right before the cat. I got that fixed and now the car sometimes runs -18 but mostly stays on -6 to -12 range on short trim and bounces from -10 to 3 on long trim. How many driving cycles does it take for it to adjust to normal .So far I drove the car 3 times
Hey Jimmy, usually it happens pretty quick. Sometimes it's best to clear the fuel trims and drive with it fresh.
Mike Becker, Senior Instructor
Thank you.liked this class. Learning lots.
Thanks Jesud! Glad you are learning a bunch!
Mike Becker, Technical Services Instructor
Jesud Garcia Jt y
I've have learn a lot from watching this video thanks guys Just one question. My car was running lean on bank 2 due to a vacuum leak. 21 short term and 16 long term during idle Well I got that fixed and now its running rich each time I accelerate. Like sometimes 8- to 13- on the long trim and 5 to 8- on short trim. The fuel trims are okay during idle Is there anything I missed? or is it normal for the car to run very rich while accelerating it.
Did you figure it out?
Wouldn't a vacuum leak affect both banks on a two bank engine excluding a Manifold leak on on one bank? Same on a bad injection or bad plug or coil pack on that bank?
to anyone watching this in the future and notices the audio is off, a way to get around this is 2 have two youtube tabs open of this video, one to watch on mute, and another to have audio playing and minimized. the time difference is ~9:40 seconds. so fast forward one to that time mark and then hit play on both of them as quickly as you can. was driving me crazy.
Hello I hope you're doing well just would like to have an idea why the hose that goes from the canister purge valve in the Gasquet it would shrink when accelerating i would really appreciate it thanks
Great video but can someone get him a glass of water for his dry throat… oh wait he had 6 glasses of water in front of him.
😂😂
Long Term is the window of time the adaptive memory dictates the fuel trim, Short Term is live data calculating to learn the parameters for the adaptive memory to update the Long Term. The O2 sensor signals lean below .45 volts & rich above .45. The Engine Controller only cares about that threshold & uses that to determine fuel trim. .. in other words the computer calculates the % of time that the O2 sensor is past the threshold of .45 volts & does that each time the threshold is crossed.
Had an envoy with a p0171 an a p0496 p0300 with long term at 35+. missing an intake vac line cap an purge valve was stuck open still checked the maf.
Hey Daniel, sounds like that thing had a bunch of issues. Got it all fixed up now?
Mike Becker, Technical Services Instructor
Great explanation on volumemetric efficiency
Thanks for watching Padraig!
Mike Becker, Senior Instructor
hi, i,m new subscriber, great video! my car is nissan skyline 300gt 2002 year. lambda is 1,017, but CO is very high 1,57-1,76. what is possible causes? thanks!
excellent instructor
Thank you!
Mike Becker, Senior Technical Instructor
Hello. 2003 Mitsubishi 3.8L V-6, 220,000 trouble free miles. Fuel economy is where it should be.
LTFT 1&2 are +12.5% at hot idle. But goes to 0% and stays there when revved to 2,500 rpm.
STFT 1&2 are 0% at hot idle. When extra fuel is sprayed on identified leak of intake manifold (leaking o-ring, I used smoke to find) the STFT immediately goes to -6 and then returns when the extra fuel is burned off.
Could this intake air leak thats affecting both banks cause the truck to go into a limp mode, giving me these codes?
P0335
P2135
P0340
Also, why does LTFT go to 0% when under load? Thanks!
HI,
The intake leak will not effect cam and crank signals or cause the vehicle to go into limp mode. There must be another issue with the system.
With a intake leak fuel trims go down under load for a few reasons. First under load the engine consumes a much larger volume of air, so the air leak affects the fuel trims much less. Also when the engine is at 2500 RPM the throttle body is open causing the pressure in the intake to be close to atmospheric pressure, which means no vacuum in the Intake. With no vacuum in the intake it will not be able to suck as much unmetered air into the engine.
Ryan Wilsing, Technical Instructor
@@GoTechTraining thank you very much! That makes sense about the LTFT.
I will check out the throttle position sensor as it seems to go back to normal when it cools down for 15+ minutes. Maybe it is overheating. Maybe I can replicate issue by getting TPS hotter with a hair dryer. Thanks again!
Great vid!! I get this code every winter and only in winter. I have absolutely, no symptoms - pont 08 vibe, purrs like a kitten. Chkd for vac leaks, intake gasket, gas cap and o2 sensor. All good. Thinkin maybe fuel injectors or fuel pressure issues. Giv me yur critique!😩
RM.
Hey Rudy, thanks for watching! The Vibes were SUPER common for intake gaskets to leak only when the engine is cold. Has yours ever been replaced?
~Mike
@@GoTechTraining No, it hasn’t. Thanks
Once again excelent teaching congrats.
Thanks Jose!!!
Mike Becker, Senior Technical Instructor
excellent class .
Thanks Vin Brown!
Mike Becker, Technical Services Instructor
What about a failed spark plug boot or leak in hose to evac.
I just found your site. I am new to this and it is very interesting subject. i just bought a new Altel 808 and it amazing to watch it on live data. I have a 1999 gmc k2500 5.7 I have replaced the injection spider and cleaned the carbon out of the intake. I Have changed the o2 sensors and it is telling me that i have a low heater out put on bank 1 sensor bank 2. I have looked at the wiring and it looks good. any ideas. The A/F is 14.7. o2;s are reading 450. The engine is high mileage, does not use any oil, the compression is 160 to 165. starts good and runs great. Thanks
@6:11 and @7:46 I really don't see how an ignition misfire could trigger a po171 po174 (lean).
Is your instruction on air and fuel correct? It appears that you are comparing the air and fuel ratio to volume by showing volumes of water. With as much air as an engine breathes, would I be able to get out of the parking lot before I ran out of gas? Shouldn't I be comparing them by weight? (The answer is yes)
I have a P0171 lean code for a Corolla 2001 with 197k miles. My Long Fuel Trims are 40.1 %. Could that be that i have a clogged fuel injector? I cleanned my MAF sensor, change my O2 sensors, change All Gaskets. Still have the code ON. Any advise would be great...
Sounds like it's running very lean Jose. Sure, it's possible it's an injector issue.
Mike Becker, Senior Instructor
P0141 replace my downstream 2xs OEM 2.4 eclipse
Bad parts? What else can cause it
Hey Randal, you want to verify the heater circuit is getting power and ground. You can confirm it by putting a test light across the heater circuit and see if it lights up when the car is started.
~Mike
I have a 1996 F250 5.8. It only has 116k miles on it and the engine sounded really good until a few weeks ago when I put about 2 year old gas in it. I KNOW THAT WAS STUPID. it was about 10 gallons. The very next day, it was rough starting up but it ran fine once it started, however, the next day, the truck was shaking, started sounding like it was misfiring, and whatever. I didnt siphon out the bad gas, instead I out fresh gas in.
The fixes I have done on it thus far are: fuel filter, cleaned injectors, spark plugs and wires, new distributor cap and rotor. and it still isnt running right. I took it to a DIY mechanic who has been a mechanic for probably 50 years and he said it sounds like the lifters. What do you make of it?
Do you think that the gas is a coincidence? I find it hard to believe adding old gas caused it to ruin lifters that were fine before. I don't buy it. I would inspect fuel trims. Maybe your gas had water in it and the truck is running lean to the point of misfiring. Not sure on that lifter idea man. I'd do some testing before jumping to engine work on a truck that sounded good.
Mike Becker, Senior Technical Instructor
I didnt think so either. My dad had said he didnt believe old gas would be the culprit, but the water content may have the engine running lean. Thank you so much. Ill take this info and work accordingly. You the man. SUBSCRIBED!
Old gas can cause an engine to run poorly. You could try adding some of that water eliminator to the tank. See if it helps, it shouldn't hurt anything. Thanks for subbing man!
Mike Becker, Senior Technical Instructor
Do you have a suggestion for this? My VW Golf TSI 2008 (BLG engine code) has a Fuel System Too Rich error. When the exhaust emissions are measured at idle all is fine, but at 2500 rpm the carbon monoxide is way too high. So the car failed inspection today. The error code is actually not present at the moment. I deleted it months ago and it didn't come back. So I forgot about it until I was reminded about it today due to the failed inspection. The error code was P0172
Hey J Wester, a rich condition is a lack of oxygen in the exhaust. It's interesting that it's only under load and not at idle. I'd take a close look at the air fuel ratio sensor and the 02 sensor. Try forcing the car rich and lean and see if the sensors respond appropriatly.
Mike Becker, Senior Instructor
@@GoTechTraining Thank you for your answer. This engine seems to be using an 02 sensor. Initially I was looking for the MAP Sensor. In this engine the sensor is an intake manifold pressure sensor combined with intake air temperature sensor. As I understand the computer uses these two values to calculate the air mass and adjusts the air/fuel mixture
Hey, thanks for the video. Very helpful. My shogun sport v6 has codes P0170 and P0173, both fuel trims. It seems to be running fine except a slight change in idling speed every minute or so (from 1000 to 700ish RPM). The previous owner has changed an o2 sensor (top of cat) but the 'check engine light' is back on. I've unplugged the MAF sensor and the idling speed increases, then goes back to normal once plugged back in. That's all I've done so far.
Any ideas appreciated! Bit of a head scratcher 🤔
Hey Mark, Do you have a scan tool that can watch data? I'd like to see what the fuel trims are reading at idle and at a moderate load. There are a lot of possibilities to what could cause this issue.
Mike Becker, Senior Technical Instructor
@@GoTechTraining thanks Mike, yes I have the torque light obd2 thing I'll take some screenshots and send them to you if you like? There's 4 sensors per bank, I'll try and get them on the same screen. What's your email?
Sure, send them to MCBecker@NGKSPARKPLUGS.com
@@GoTechTraining emailed you 👍
Question: I have a 2013 F30 BMW 328i. I got codes P0171 and P0172 at the same time. The codes contradict each other. My "start/stop" feature in the car doesn't work anymore. Any idea what the issue is?
Did you ever find out the problem? I’ve been looking everywhere for this, but I have not had luck.
thanks so very much for this wonderful technical talk
Thanks for watching Fru Che!
Mike Becker, Senior Technical Instructor
Great thorough and informitive class.
BTW, how's life in fondy?
Hey Geoffrey, thanks for watching! Life in Fondy is....well life in Fondy, haha! Plenty of road construction lol.
Mike Becker, Senior Instructor
Can y'all do some post carb, pre obd2 fuel trim videos PLEASE!? Reading blinking lights sucks! Do u have insight?
My issue on a poor random idling 92 Nissan MT KA24E KC XE no CEL per Nissan. I'm sick of it becoming this parts cannon.. still have all original parts on hand.
My 2003 car service manual indicates that if 0.98 < lambda < 1.02 at idle and operating temperture ( > 80 C) it is a good condition.
I have bmw e46 it start ok but it not reving out what would cause that.
They communicate with each other.
Was just informed about this site; if you're going to do "teaching"/"explanations " of ratios, many will not know if you're talking about weight or volume.(e.g. is 14.7:1 by weight or volume?). Having been a chemist, UNLESS otherwise stated, it is always by WEIGHT. ON the other hand, if your referring to gases("room" temperature), then by volume. It would be helpful to students to clarify this point.
How do you check for a p1093?
Fantastic lecture!
A connected topic: anybody knows how to deactivate learning procedure on a flex fuelcar (volvo in this case) . Thre is no ethanol content sensor but computer leatns thru the Lambda readings and injection pulse duration ...causing many problems when driving regular fuel. I am tired iwth them so simply would love to deactivate the process but there is no obvious way to do so. I can only reset the content to the default value of 50%. Then the crap learns and sometimes rich 70% with the engine to be floode on a cold start.
Ideas?
Thank you very much! That seems crazy that the car would "learn" such a high ethanol count with no ethanol in the fuel..what's it truly learning? Are you sure you don't have something wrong causing it to read so rich? I've seem the algorithms get stuck, GM especially, but after resetting they are usually ok again. Is there maybe a software re-flash for the car or something?
Mike Becker, Senior Technical Instructor
@@GoTechTraining I missed your reply! Thanks.
There is a counter for ethanol content and each time you fill the tank the learning algorithm is initiated. It learns thru the lambda and injections timing. Therefore if there is something wrong with with fuel to sir ratio it interprets it as alternate fuel percentage in the tank and store ty he ethanol content reading. Next time you want to start in cold conditions it ask long injection time to account for ethanol and the engine is flooded.
And I have a bi-directional tool so I am able to reset the content to the default (50% !) value.
So yes, apparently there is something wrong but it is do tough to find out with this intelligence involved 😂.
Would love to deactivate it first but have no idea how. Thinking about replacing the ECU for similar engine one but not accommodated as the flex fuel.
great class mike I'm staring learning of this new computer systems. I'been working on heavy equipment diesel engines for 20 years and now i want to learn more of this new vehicles.
Hey Antonio, welcome to the headache that is cars ;) Good luck!
Mike Becker, Senior Instructor
Very useful information sir thank you
Sir I have Chevy suburban 2007 and I'm getting codes p0172 and p0175 system too rich on both banks and ratio is showing short fuel trim at 0 and long fuel trim at -25 what do you suggest me to do first
Thank you for watching A Rahman! On your suburban, these were very common to run into fuel composition calculation issues. There should be a PID on your scanner saying ethanol content. Verify that seems right. if you are running standard pump gas we usually look for 5-10%. Anything higher than that can give you issues. Ethanol requires higher fuel volume which could be exactly why your truck is running rich.
Mike Becker, Senior Technical Instructor
Very informative. Thanks for the taking the time. You teach a great class. Your step by step process is unmatched. Thanks for passing the knowledge to us all.
A RAHMAN fuel pressure regulator.
Dona fuel pressure leak down test. Must hold 55psi for several minutes after key off.
My question about the Lambda reading on a scan tool is , for an example, 1.2 on your lambda chart on your video training, when you read this value on a scan tool , is the computer on your car taking fuel away because the fuel trims rich ? If someone can answer the question I would be thankful!
Hello I own a 2005 Crossfire I have codes Chrysler with code P0172 and P0175 > I have had problems I also code P0239 Air induction blower failed but I hear it running at start up. I am a senior citizen and can't afford to take it to a shop if I could find one my next thing is take it off the rd Most shops do not want to work on this car since it is a Bastard car neither Mercedes or Chrysler or individual shops will not touch this car. It has a Mercedes engine 3.2 Liter V6 . I replaced all injectors and plugs wires and and individual coils the car runs great but as soon as I get close to the emission station it throws the P0172 and P0175. I looked for loose vacume hoses and I found one and I fixed that. My car is due in February and I don't know what I can do get this to pass emission. In a few years the car is exempt emission if I use Historic tags. I don't drive car much but the emissions will not allow me to go through the test for a week. Like I said the car runs great but soon as I get close to emission station it throws codes. I drove it for a week and today it did same thing 3 times in a row I went to the emission station. How frustrating.
My car is LTFT -10.3 ? but everything like 02 doing as it should thorts pls
Hey KComputers, curious, what are you STFT when the LTFT is -10.3? Are they hovering 0? A -10 trim shows you are running slightly rich. What kind of car is this on?
Mike Becker, Senior Technical Instructor
Very informative... thanks for taking the time.
Thank you Mike!
Mike Becker, Senior Technical Instructor
@ThePariss333 Well, good thing you can skip around in the video then...or play at 2x speed!
Mike Becker, Senior Technical Instructor
I'm also hearing a puff sounds like a vacuum leak . I sprayed starter fluid but not really good at that. It sounds like it's coming from under the intake is there a gasket on it for a PT Crusier 2005 non turbo are they expensive? Also could a purge Solenoid make a puffing sound if stuck open?
Kathy, check out the fuel trims with a scanner. That should lead you down the right path as to whether you have a vacuum leak or not.
Mike Becker, Senior Technical Instructor
@@GoTechTraining I don't think people are hearing me I have NO power to my OBD II port.
You should get a parts store to scan your car to give tou some direction@@GoTechTraining
I'm experiencing pre detention at half pedal. No high tech tools. No codes "OBD1" or dash lights. I'm debating fuel trim or distributor issue. Would one always get a code with fuel trim?
Depends on the car. Most newer cars will set a fuel trim related code once long term fuel trims exceed +/- 10%. What kind of car is this on? Are you running the proper fuel?
Mike Becker, Senior Technical Instructor
Thank you for your reply. I actually got annoyed with the car and pulled the distributor, there was an oil Mark on the 3 leaf clover so it was slightly off. 94 Fleetwood 350 with Optispark. Fixed now. Love your vids. Am curious, code reader on dash "no codes" I was told buying an actual reader would not show anything more than what I can already see. Is fuel trims even on the $5k snap on obd1 readers or is it only obd2?
My 2010 Chevy malibu I have the po172 code engine will nit start the oil has gas in it the MAP sensor checked out ok any ideas that would make bank 1 rich
So a peged out negative -25 short term fuel trim open loop fault is super rich problem
I just replaced fuel injectors for 2004 prius, after two weeks check engine po172. Appears. Please help.
My 03 F150 Lariat 5.4 keeps giving me a P0401 code and negative trims around -12 to -16. I have replaced EGR valve, DPFE sensor (and hoses), EGR tube, EGR vaccum solenoid, IAC valve, plugs, coils, intake manifold, fuel injectors, and EVAP purge solenoid...
Thank you for the knowledge
thanks for this video
every 200 km I have 2 codes p0170 and p0173 ,car running fine,only check enginel ight. 2006 Mercedes -benz w203 C230 V6 sport-sedan M272
Ayy I got a GTO to lol but I’m watching this vid for my Ctsv
We have sold the GTO now. IT was time for it to go away. Poor thing sat most of the time.
Mike Becker, Senior Technical Instructor
How do I delete my 02 sensors
If a fuel pressure regulator is bad, will it always leak? Or can it still be bad and not leak?
Hey M.Night207, what kind of pressure regulator are we talking about? The old school vacuum diaphragm one? If that's the one, then ya, generally speaking it will be leaking if it fails.
Mike Becker, Senior Technical Instructor
Technician B is pretty correct in my view
wow your the best man, good job
Thanks Raed Alyamani! Glad you enjoyed the video!
Mike Becker, Technical Services Instructor
I enjoy watching !! thanks 👍🏼
P304 code & P0174. Have 2009 Ford escape 3.0l. How does the miss fire possibly cause my lean code?
I have a 03 dodge ram 1500 4.7 and have bank 1 to Rich replace the injectors and fuel regulator and both 02 sensor's n the map sensor but it still idles rough to where it almost dies the truck doesn't have EGR valve
Hey Floyd, are the injectors good quality or Ebay specials? I've heard of cheapy injectors causing issues. Can you force it lean?
Mike Becker, Senior Technical Instructor
@@GoTechTraining I bought them on Amazon and they have 4 holes instead of factory's no I can't
I have a 06 VW beetle 2.5l. I have a p0171 code. Did a smoke test and no vacuum leak was detected. Car is running rough on idle and reading short term 25% and long term 20%. I changed the maf back in July and it was running great until now. No maf code or anything when it started to have problems. I was told to replace the 02 sensors. Please help.
Is it possible your MAF went bad again? How does it react under WOT?
Mike Becker, Senior Technical Instructor