Not only is the gas cap tight, but I replaced the old with a nice new OEM cap.
thanks
I have access to most of the diagnostic tools where I work. I'm friends with a few good mechanics too. Thing is they are not chevy certified nor do they work on these common problems all the time. We have a smoke machine that will tell you where the leak is coming from and we tried that but didn't see any leaks in the system at all. I think I have it narrowed down to the wire harness at the vent solenoid at the rear of the car.
Thanks for the reply