Thread: P0420 code

Hello I am new to this forum,

I have a 2006 Grand Prix with a supercharged engine. I am looking to see if there is anyone out here in Cleveland that knows how to program my computer to get this P0420 code off my car?


There is no funny smell coming out of exhaust, car runs fine. The guy at Autozone said it's likely there is tiny leaks in cat converter and sending a message to my computer that there is a leak. Any help would be greatly appreciated.

Thanks

Liza

The code is saying that likely your cat converter is failed/failing and that you need to replace it.

Its a slim chance that its just the rear o2 being faulty, but very unlikely.


P0420 Error Code: Catalyst System Efficiency Below Threshold (Bank 1)

I believe you need a 04-05 pcm to tune it if you wanted to delete the code or get a hi flow cat.

High flow cat will still set his check engine light off, flows far too well for what the car wants to see.

I meant tune it out with the high flow cat

parsonsl1,

I agree with "Fivefingerdeathpunch", consider having the vehicle inspected by a certified technician for an official diagnosis. They will be able to offer more information after inspecting the vehicle.

Please keep us posted.

Louis
GM Customer Service