I was just going through this problem on my 97 tj. I changed the fuel pump and filter,plugs,wires,cap,rotor,cps sensor and was still missing. I was getting very discouraged until I found this video. I went online but was having a hard time finding the mopar brand. Everywhere seemed to be out of stock. I ordered some ac delco top engine cleaner for 23 bucks. Now my jeep runs beautifully. I can’t imagine how much money is spent on parts trying to fix this problem. Had I not seen this video I would have kept buying sensors then searching for vacuum leaks I would have burned the thing to the ground by that point as it was super depressing. Thank you so much for this video. For anyone unsure how to use it. You just disconnect your air management from the throttle body then start the engine. Spray directly into the throttle body until can is empty. If it stalls re start and continue. When the can is empty shut engine for 15 minutes then restart and run above idle until smoke clears (there will be a lot of smoke) my wife thought my jeep was on fire so don’t be alarmed by the volume of smoke. Once the smoke clears take it for a ride. I held mine at around 3 thousand rpm’s. It all cleared out in no time.
Hey Lee, thanks for your comment. I'm having the same problems with my 02 TJ. I recently changed the fuel pump, injectors, plugs, wires, and everything else, but it still has misfires after going 70 miles per hour or 3000 rpm. I'm going to try this, and I hope it helps.
UGH!!! Been dealing with cylinder 6 issues for more than 6 months! I HATE JEEP! And I HATE Jeep dealerships! I have a new coil pack, new plugs, wires, and catalytic converter. Turned out, my #6 and #4 misfire codes was not fixed by replacing my Coil Pack, Spark Plugs, and Wires. Took it back to my mechanics several times. Weren't able to fix the problem. Jeep told me a couple of months ago it was my catalytic converter. My mechanics also told me that. I replaced the cat. Took it to Jeep in State College, Pennsylvania (I live in Chicago) recently, after it didn't want to start, after driving 11 hrs. Hmm. One of the worst Jeep dealerships in the US. 🤬They said one of my sparkplug wires was "loose". Took it in for in-depth diagnostic. Said my coil, plugs, wires, air intake, and everything on that long list of possible issues in the 6 & 4, passed - except they "thought" it "may" be the Fuel Injectors. I'm out of ideas, options, and $$$$. This is one of the 2 worst vehicles I've ever owned. Since day-one when I bought it brand new! It's been in the shop constantly! Can't buy another car at this time. At one time, I even complained to a notorious mob boss about Jeep.
You can Ohm out the injectors to clear them as a possible cause. Does it misfire at idle? Or does it misfire at speed? Or All the time? That may clue someone in. Get on the jeep tech forums and ask for some help. Even a weak battery can cause it. Have the battery tested and clean any corrosion on the connectors.
Hi I have a 2007 Liberty 3.7L V6, 117,000 miles. Owned it since 67,000 miles. It operated perfectly for the first 30,000 miles and then it started getting a #1 Cyl misfire code P0301. It also seldomly gets a #1 cyl fuel injector circuit open P0201. It must be a very mild fault as the misfire freeze frame data shows it always happens at less than 350 rpm and when cleared it comes back immediately at next startup, cold or hot. So it seems to only happen once on startup as its moving up to regular idle speed. The miss isnt noticeable when driving or idling. Its getting 15.5 mpg fuel mileage. Doesnt burn oil. Doesnt smoke. Has great power. I've changed plugs and coils but no difference. Cleaned air intake, air filter, and ran cleaner through system. I've cleaned and inspected the injector plug and all wires but no difference. Dry / wet compression test of #1, 3 and 5 cylinders all read good: 160 / 175 psi. I'm wondering if there's a mild wire defect for that injector, or just a flakey connection somewhere. Has anyone tried to use a new set of compatible gauge wires and run them to a place closer to the injector control? I can't see where the wires go though. I'm not sure if I should just live with this, or troubleshoot it more. I don’t care about the engine light as we don't have emission requirements. Now that I know the compression is good, I'm not so worried about it. Any suggestions of what to do next? Thanks! Pics are of what I'm curious the injector wires are headed.
i have a 2017 jeep wrangler with the 3.6 liter v6 engine and i have a misfire on cylinder 4 and i just put new spark plugs in and the coil pack on cylinder 4 and the check engine light came back on today telling me code P0304 cylinder 4 misfire what could i do to make the code not come back and the misfire to stop
I have had random cyl6 misfire, especially with ethanol gas. My supercharger makes me use hitest but you can't find premium unleaded without ethanol now, just regular.. so I do a seafood fog once a month and hot soak /fog it with seafoam. And that helps. I'm only getting 9 mpg so something is wrong... either water into the fuel tank that is known to happen at the sensor seal (hassle to address for sure), a bad coil pak, fouled plugs (only 20k on them but with the above, could be). It's winter here in PA, so I'm holding off til at least March to tear ol Rubus down & give him a check up.
I have a 2002 Jeep Wrangler with the straight 6 in it that has got a misfire on number 3 cylinder but I can clear the codes and drive. The Jeep only could come back and it starts flashing when I hit the brakes only when I hit the brakes. Does the check engine light start flashing? I have to stop put the computer back on it, clear the codes and I can drive again and it drives good. But soon as I put my foot on the brakes that code comes back and it goes back to misfiring again. Do you have any idea what to check or what to do?
I got an 04 WJ and an 03 WJ. both feel like they misfire but only my 04 throws a P0303 code. I've changed the plugs, new air and fuel filter. What about the injector?
I was just going through this problem on my 97 tj. I changed the fuel pump and filter,plugs,wires,cap,rotor,cps sensor and was still missing. I was getting very discouraged until I found this video. I went online but was having a hard time finding the mopar brand. Everywhere seemed to be out of stock. I ordered some ac delco top engine cleaner for 23 bucks. Now my jeep runs beautifully. I can’t imagine how much money is spent on parts trying to fix this problem. Had I not seen this video I would have kept buying sensors then searching for vacuum leaks I would have burned the thing to the ground by that point as it was super depressing. Thank you so much for this video. For anyone unsure how to use it. You just disconnect your air management from the throttle body then start the engine. Spray directly into the throttle body until can is empty. If it stalls re start and continue. When the can is empty shut engine for 15 minutes then restart and run above idle until smoke clears (there will be a lot of smoke) my wife thought my jeep was on fire so don’t be alarmed by the volume of smoke. Once the smoke clears take it for a ride. I held mine at around 3 thousand rpm’s. It all cleared out in no time.
Hey Lee, thanks for your comment. I'm having the same problems with my 02 TJ. I recently changed the fuel pump, injectors, plugs, wires, and everything else, but it still has misfires after going 70 miles per hour or 3000 rpm. I'm going to try this, and I hope it helps.
Can you make a video showing the process?
My 01 tj threw the P300 code . Intake tube on top of throttle body was extremely loose. Appears have fixed the problem. Hope this helps someone.
Nice video thanks you for shared
UGH!!! Been dealing with cylinder 6 issues for more than 6 months! I HATE JEEP! And I HATE Jeep dealerships! I have a new coil pack, new plugs, wires, and catalytic converter. Turned out, my #6 and #4 misfire codes was not fixed by replacing my Coil Pack, Spark Plugs, and Wires. Took it back to my mechanics several times. Weren't able to fix the problem. Jeep told me a couple of months ago it was my catalytic converter. My mechanics also told me that. I replaced the cat. Took it to Jeep in State College, Pennsylvania (I live in Chicago) recently, after it didn't want to start, after driving 11 hrs. Hmm. One of the worst Jeep dealerships in the US. 🤬They said one of my sparkplug wires was "loose". Took it in for in-depth diagnostic. Said my coil, plugs, wires, air intake, and everything on that long list of possible issues in the 6 & 4, passed - except they "thought" it "may" be the Fuel Injectors.
I'm out of ideas, options, and $$$$. This is one of the 2 worst vehicles I've ever owned. Since day-one when I bought it brand new! It's been in the shop constantly! Can't buy another car at this time. At one time, I even complained to a notorious mob boss about Jeep.
Don't hate the jeep, hate the mechanics that are just throwing parts at it, instead of diagnosing the actual issue
You can Ohm out the injectors to clear them as a possible cause. Does it misfire at idle? Or does it misfire at speed? Or All the time? That may clue someone in. Get on the jeep tech forums and ask for some help. Even a weak battery can cause it. Have the battery tested and clean any corrosion on the connectors.
Hi I have a 2007 Liberty 3.7L V6, 117,000 miles. Owned it since 67,000 miles. It operated perfectly for the first 30,000 miles and then it started getting a #1 Cyl misfire code P0301. It also seldomly gets a #1 cyl fuel injector circuit open P0201. It must be a very mild fault as the misfire freeze frame data shows it always happens at less than 350 rpm and when cleared it comes back immediately at next startup, cold or hot. So it seems to only happen once on startup as its moving up to regular idle speed. The miss isnt noticeable when driving or idling. Its getting 15.5 mpg fuel mileage. Doesnt burn oil. Doesnt smoke. Has great power. I've changed plugs and coils but no difference. Cleaned air intake, air filter, and ran cleaner through system. I've cleaned and inspected the injector plug and all wires but no difference. Dry / wet compression test of #1, 3 and 5 cylinders all read good: 160 / 175 psi.
I'm wondering if there's a mild wire defect for that injector, or just a flakey connection somewhere. Has anyone tried to use a new set of compatible gauge wires and run them to a place closer to the injector control? I can't see where the wires go though.
I'm not sure if I should just live with this, or troubleshoot it more. I don’t care about the engine light as we don't have emission requirements. Now that I know the compression is good, I'm not so worried about it.
Any suggestions of what to do next? Thanks!
Pics are of what I'm curious the injector wires are headed.
i have a 2017 jeep wrangler with the 3.6 liter v6 engine and i have a misfire on cylinder 4 and i just put new spark plugs in and the coil pack on cylinder 4 and the check engine light came back on today telling me code P0304 cylinder 4 misfire what could i do to make the code not come back and the misfire to stop
I have had random cyl6 misfire, especially with ethanol gas. My supercharger makes me use hitest but you can't find premium unleaded without ethanol now, just regular.. so I do a seafood fog once a month and hot soak /fog it with seafoam. And that helps. I'm only getting 9 mpg so something is wrong... either water into the fuel tank that is known to happen at the sensor seal (hassle to address for sure), a bad coil pak, fouled plugs (only 20k on them but with the above, could be).
It's winter here in PA, so I'm holding off til at least March to tear ol Rubus down & give him a check up.
I have a 2002 Jeep Wrangler with the straight 6 in it that has got a misfire on number 3 cylinder but I can clear the codes and drive. The Jeep only could come back and it starts flashing when I hit the brakes only when I hit the brakes. Does the check engine light start flashing? I have to stop put the computer back on it, clear the codes and I can drive again and it drives good. But soon as I put my foot on the brakes that code comes back and it goes back to misfiring again. Do you have any idea what to check or what to do?
Im having the same issue, did you figure it out?
How do you spin the valves?
Drive it at 2500 rpms and up.
👍🏻🇦🇺
I got an 04 WJ and an 03 WJ. both feel like they misfire but only my 04 throws a P0303 code. I've changed the plugs, new air and fuel filter. What about the injector?
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