I have a '07 Tahoe. There is a strong gas smell coming from reat driver side of vehicle. Can't find any gas leaking anywhere. I've replaced the vent valve solenoid. I pulled the purge valve off and checked it to see if it was stuck open. It checked good. I also dropped the charcoal cannister and shook it around to see if there was any raw fuel in it and it didn't seem like it was. Any other ideas?