alright i reading a few of the threads last nite for the p0420 code...n i believe the lady from autozone said it was bank 2...so ive learned thats the 02 sensor after the converter...but heres the thing ive tooken n the 02 monte carlo...n they said thats it is already aftermarket...so wats best?...actually check out the sensor?...or get the emulator thing?

 

Tell us more about the car. Anything done to it? Year, Engine.

 

everything stock...its 2002 3400...no kind of mods as far as emissions go...only thing ive done is a sound system...but thats it...n as far as the aftermarket cat converter its oem standards...so please help...its that time of the yr

 

I'd honestly probably just do the fake if I didn't want to deal with the code, but if it is a faulty Cat you could be having problems.

 

I agree, I'd make sure there's nothing wrong with the cat and then put an emulator in.

 

srry guys wrong info...went to local autozone today and had it scanned...but came out with bank 1 efficient below threshold...it gave me lik four possible reasons...an oil leak...vacuum leak...a bad cat...but i doubt that...n misfiring spark plugs...i kno this is crazy but would a tranny leak set it off?