I don't know if anybody has had this problem before but I had it happen to two of my Mustangs, gas fumes smell through my air vents, I fixed the problem by replacing Vapor Canister Purge Valve, so I thought I would share.
Interesting I have that smell coming through the air vents but only when the car is running rich on a bama tune. No tune and no richness = no smell through air vents for me. Thanks for sharing.
I've had the same problem, however, in my case it was just the vacuum hose that ran into the vapor canister.
my bama tune ran so rich my eyes were watering at lights while trying to get to the dyno. The only time I didn't like side exhaust....