2003 grand am

ENGINE LIGHT CAME ON HAD THE CAR CHECKED SAID THE O2 SENSOR. THE LIGHT CAME BACK ON SAID THE CATALYTIC CONVERTER THE LIGHT CAME BACK ON SAID BACK O2 SENSOR REPLACED IT THE AGAIN. LIGHT CAME BACK ON SAID O2 SENSOR REPLACED AGAIN SO FAR I HAVE REPLACE THE FRONT AND BACK O2 SENSOR AND CATALYTIC CONVERTER,COIL PACK,SPARK PLUGS AND COILS. AND EVERTIME I GET THE CAR CHECKED IT SAY THE FRONT O2 SENSOR. PLEASE HELP:crying:

Welcome to AF !

What size engine and how many miles ??

Could be an injector stuck open making the fuel mix to rich.

You can check thier resistance with a multimeter acrossed the injectors terminals, should read 1.95-2.3 ohm on the 4 cyl, and 11.4-12.6 ohms on the V6.


What brand of converter and O2 sensor ??

it could also be wires after o2 sensor connector (pcm) side

Yeah but not likly 3100, unless the PCM has been pulled down from the mounting bracket.

It could be the actual wires to the sensor(s) thats bad, eitehr due to melting or ripped off from driving over something.

My GTs downstream O2 wire was hanging low after the header install. I noticed one day I had a tree limb stuck up in there draggin/yanking away at the wires. Luckily it didnt damage anything.

check your 10A O2 sensor fuse, should be left side of the dash when you open drivers door, lift that cover in the corner

Thank you all but i had a leak in my exhaust they did seal the catalytic converter all the way around