Quote Originally Posted by HighOctaneRacing View Post
The shop may not even cut out the cat because it is considered illegal. I would spend the coin and get a ZZP catless down pipe with a bung so you can do the non-fouler trick to avoid getting the P0420 code.

The ZZP o2 emulater works flawlessy but it does not work on 04+ models and a 2008 GP cannot be tuned to remove the P0420 code because they are locked down from the factory. basically the only thing that will work correctly is the non-fouler trick. It's very cheap and easy to do provided you have the o2 bung.

I always wondered... Why doesn't it work in the 2004 gp?