rbregger

Actually, it could be a few things. The "probable causes" that printed out of the OBDII tester for P0449 were: 1. Purge or vent solenoids defective 2. Connector or wiring problem 3. Fuel saturated vapor canister 4. Failed EVAP vent solenoid Using a multimeter, I checked the resistance across the vent valve solenoid coil and found it to be open. A good solenoid measures about 20 ohms. I stopped troubleshooting there, bought a replacement vent solenoid unit, reset the CEL, everything good.

kschein: I followed "odayflor's" advice from another posting and found the exact replacement vent valve solenoid/filter unit at Advance Auto Parts for $22.99. I posted some pics in this thread: http://www.gm-trucks.com/forums/index.php?...71&hl=p0449