O2 Simulator (Oxygen Sensor Simulator)

Oxygen Sensor simulator for Downstream Sensor #2 - voltage rises to 0.6V then falls to Zero volts using a 555 timer and some capacitors/resistors to tune the monostable circuit to the correct voltage for car ECU. Circuit allows for offroad exhaust system with no catalytic converter to avoid CEL (Check Engine Light).
Thanks to:
mkiv.com/techarticles/oxygen_sensor_simulator/index.html

[@RamyAbbas]

Can we have a gerber file?

[@ahmedyahia6056]

Can you send us the wiring diagrams pleas

[@MarcusBerking]

It was built adhoc with a random search on google - cant remember which example was used

[@greece4surf]

but sensor 2 must somehow follow sensor 1, So shouldnt there be a direct voltage input of sensor 1 to this circuit. or does the ecu even accept generic signals?

[@greece4surf]

oh i think u did that

[@greece4surf]

so basically youre creating a generic O2 sensor1 signal and redirecting this to your circuit which is damping the oscillation and outputs this to ecu? Aren't there any other signals monitored aswell or is this sufficient?

[@MarcusBerking]

It’s a timer based system for downstream o2 - it doesnt have any inputs so it just simulates a signal slowly bouncing within the downstream (cat efficiency o2) upper and lower limits - some designs use a comparator circuit between upstream and downstream to see if they match = failed cat

[@Mr.Thermistor7228]

​@@greece4surfNope that's not how it works. Sensor 2 has no affect the engine operation

[@prasadpawar2460]

circuit digram plzzzz

[@MarcusBerking]

There are plenty of circuits on google - I cant remember which one I was experimenting with sorry

[@Mr.Thermistor7228]

It's literally on video

[@sniffles117]

?

[@MarcusBerking]

sniffles117
For offroad 'no catalyst' applications - stops CEL