Quote Originally Posted by rascal View Post
After installing my ZZ performance ss intercooler and my headers I now have the following codes that I cant seem to make go away. Suggestions?

Codes
P0171 system too lean Bank 1

P0304 cylinder 4 misfire detected

P0401 Exhaust Gas Recirculation Flow Insufficient Detected

Can anyone help me
You have a vacuum leak. What gaskets did you use? The ss i/c requires a Gen 5 gasket between the i/c core and lim and a Gen 3 gasket between the i/c core and s/c. Get some throttle body cleaner and start spraying while the motor is running all around the i/c core,lim and s/c. When the idle picks up u found the leak... Is it idling like crap?Hopefully you just knocked a vacumm line loose or your gonna have to tear it back apart