^ agreed. Your charcoal canister is loaded with gas fumes, which is causing your gas filler to do that. The purge solenoid doesn't contain enough voltage to charge the coil, releasing the gas fumes back into the intake, which replacing it should help. Also, AutoZone's scan tool is just a generic scanner, cheapo. If you want to see what its supposed to read, get one that has access to PIDs to read the voltage on each sensor/actuator. Most generic scanners with PIDs will be for this particular DTC, EGR & EVAP Emissions Control. Should read above .1v-5v max for reference (5v=signal voltage at max load, .1v=lowest reading and solenoid closed).
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; 05-27-2013 at 08:12 PM.