Quote Originally Posted by Bedwards View Post
I have a 2001 Grand Prix GT with the SS M90 kit as well. I have a rough idle and the RPM is all over the place when it's cold. I would love to hear the answer to this question as well!

P.S. How are you running a 3.8" pulley without more flow mods? I get knock retard with a 4.0" pulley and I have a CAI, headers and full 2.5" exhaust.

Id like to see a scan of your setup. You're tune must blow