P0420

[maroman88]

97 lt1 m6
i am stuck here, i replaced the o2 sensor and the problem didnt go away, nothing rattling in the cat, no funny smells or anything that would indicate a bad cat, short of getting it tuned and the rear o2's tuned out, whats left to check?

and just to confirm p0420 is for the driver side correct?

[The_Bishop]

Look here: P0420 (http://www.obd-codes.com/p0420)

Fairly sure that bank 1 is the driver's side.

[JSPERFORMANCE]

The code is the indication of the cat being bad.. If the Rear O2 sensor was not functioning, the PCM could not have set the P0420..

[sweetbmxrider]

Yup, you aren't experiencing total failure yet but the cat isn't doing its job. Driver cat is correct.

[L695speed]

This code is the bane of my existence.... Not on an F body though, I've had it on my Subaru. Replaced the whole exhaust system 3 going on 4 years ago. The muffler rotted already, and that damn code is on. How the hell can a cat go bad in 3 years I don't know. But yeah, I've read in my case its the cat or the O2 sensors, some replaced one or the other and it went away. Some replaced it all and still have the light. Thing that bugs me is, it does go away for a short time (once it did so to get it through emissions) then it comes back. Hope you have better luck with your light than I did with mine. I'm due for emissions this year and the daily has a whole rap sheet of other problems so I'm trading in before I have to get it through.

[maroman88]

oooooo fine i guess ill replace the cat

magnaflow factory replacements any good? best price i saw so far
http://www.summitracing.com/parts/mpe-23517/overview/year/1997/make/pontiac/model/firebird

[sweetbmxrider]

This code is the bane of my existence.... Not on an F body though, I've had it on my Subaru. Replaced the whole exhaust system 3 going on 4 years ago. The muffler rotted already, and that damn code is on. How the hell can a cat go bad in 3 years I don't know. But yeah, I've read in my case its the cat or the O2 sensors, some replaced one or the other and it went away. Some replaced it all and still have the light. Thing that bugs me is, it does go away for a short time (once it did so to get it through emissions) then it comes back. Hope you have better luck with your light than I did with mine. I'm due for emissions this year and the daily has a whole rap sheet of other problems so I'm trading in before I have to get it through.

That will happen with aftermarket cats.