P0420 but asymptomatic

[jkelley]

I have a 2000 Chevrolet camaro 3.8 with 130k. I just finished installing a new ICM for a previous misfire code. Now two days later, I'm throwing P0420 but nothing is wrong with my car as far as how it drives. But I need to get this code cleared in order to pass smog. Any suggestions of where to start?

[Bonemaro]

Re: P0420 but asymptomatic

Since P0420 is the O2 sensor after the cat, you can either replace the converter, install an O2 Sim or find someone with HPTuners and delete the P-code from the database.

[jkelley]

Re: P0420 but asymptomatic

O2 sim? I'm sorry, is that like a fake o2 sensor or something?

[jkelley]

Re: P0420 but asymptomatic

Btw, I have had this code before and my performance was completely diminished because it was my cat converter. It was replaced around 2 years ago and it got rid of the code

[whitdog54]

Re: P0420 but asymptomatic

go clear the code, see if it comes back. Also check the wiring around the O2 sensor and the sensor itself

[jkelley]

Re: P0420 but asymptomatic

Okay I'll do that tonight, let me know about any other suggestions. Much appreciated guys

[nitetime_pr]

Re: P0420 but asymptomatic

I always thought 420 was a code for something else...:naughty:

[ssms5411]

Re: P0420 but asymptomatic

Probably the O2 sensor since you had your CAT replaced. but if its there after you replace the O2 then your CAT is bad. might want to tap on the CAT housing to see if you can hear in loose pieces rattling around.