I have a great idea, get an interceptor gauge so you can clear you codes yourself and also watch your iat2's and knock =P.

 

well just installed this mod. I just have to clear the code tomorrow . Stay tuned to see if it works

 

I have the plug extender on my car. i drilled out my cat cause it kept giving me problems. The extender fixed the catalytic deficiency code. I also had the lean code. It was the oring under cylinder 2 injector all shrunk up and missing half a side. Damn GM techs. I put all new orings in and it fixed the lean codes and cylinder misfire code i was having under hard boost. check it out

 

Well i tried this and it doesnt work. Im still getting a p0420 code any other things to try??

 

very very true.......my brothers HHR through this same code after his CAI install........and HIV on here with his 07 SC threw the same code right after his cold air intake.......i wouldnt worry about it

 

you sure everything is right? this is pretty much universal to any car, and it works on C6 Vettes, G8 GTs, etc... I don't see why it wouldn't on the Cobalt, I haven't personally used it on my Cobalt, but I have on previous cars

 

I tried erasing the code again...Ill post if it comes back on. Its pretty easy 2 do

 

i know my code keeps popping up as well but ima take it off and check everything out again my hole wasnt drilled to 3/8 does that make a difference

 

there needs to be no "restriction" where the two pieces connect

 

Well i drilled it out and everything...I get about 30 miles and the light comes back on