mustangfan22

has anyone used a resistor in place of a exhaust O2 sensor? The store bought one is expensive, Im looking for a cheaper alternative.

mdvaldosta

Well then you would defeat the purpose of even having an O2 sensor. An O2 senser returns VARIABLE resistances to the cpu, letting the cpu know if you are running lean or rich so it can compensate. If its the front o2 sensors on your mustang then NO! get a replacement one. If its the rears then yes you can use a resistor and send a fixed signal to the cpu since all it does is tell the cpu and your check engine light that your cat's are working properly. Im not sure what resistance resistor you could use, you could check someone elses mil's to see what they read, or you could check the resistance being sent back to from the rear ones after the car is warm.