Code P0420 [Archive] - Forum


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01-30-2006, 04:50 PM
I had a bad catalytic converter. About a year ago it got really plugged and had it replaced. Not at a dealer but at a local place that has been doing exhausts forever and I know they do a good job. 2 weeks after that my check engine light come on. I haven't done anything with it until today when I had the code checked.

I'm getting a P0420 code. It also says bank 1. It's not a hi flow just a normal converter. Could it take 2 weeks for this code to come on after the converter change? If so should I get the O2 simulator?

01-30-2006, 05:01 PM
sounds like an 02 code

01-30-2006, 05:05 PM
ive got the same code and it came on about 2 weeks after i had my CAT replaced.
im getting the 02 simulator. ill let u know if it helps.

the thing is its throwing another code as well so i duno if it will turn off my light

01-30-2006, 05:17 PM
high cat inefficency. what us WRX guys do is get a HELP! Brand spark plug anti-fouler, its a perfect mechanical fix

01-30-2006, 05:50 PM
Hey laxjax. Yes please keep me posted. I would like to know if that fixes you problem. Thanks for the reply.