Did you check your charcoal tank? Its used in the EVAP system and feeds the fumes from your gas tank to your intake manifold. Ever overfill your gas tank on a hot sunny day? That can be a huge cause of the purge valve. The purge valve is located between the charcoal tank (above the fuel tank) and the intake manifold and its considered an EPA regulation, also to enhance your MPG/emissions.
-Fuel Additives (such as octane boosters)
2009 Cobalt LS XFE U74
Mods: K&N Typhoon Intake, Option Cat-Back Exhaust, Cosmo Short shifter, Maxxim Ahead 17X7's, MPx shorty antenna, FE5 Strut/shocks, Tein S Techs, Moog endlinks, Moog spring seaters, ZZP shorty header, LSJ downpipe, LNF front grille
Last edited by 5t3alth; 04-23-2013 at 11:22 AM.