Hello I have a 1997 deville concours. I notice when I put the heat on I can smell gas coming through the vents in my car. However I don't have the smell when I press the recirculation button. I just had the O2 sensor replaced today, but I smelled this before that got replaced. Earlier this year I had the recalled Fuel Rails replaced by the cadillac dealer, but I'm not sure if that would cause the smell. Anyway has anyone else had this problem?