Motor City Mad Man
Enthusiast
Is your 96 a GTS? If so I had the same problem until I found out that there is supposed to be a screw on gas cap underneath the hinged gas door that you see from outside the vehicle. Since it came without the screw on gas cap or the part it screws into I had no idea it was missing and thought that the hinged gas door was all there was. It later made me think that the car was probably raced and that the gas cap and part it screws into were removed for quicker filling at the track. Oh well, I had a new gas cap put on and all is well and the car has never been a problem even if it was raced by the previous owner. I have a feeling this is your problem too. I have since also bought a locking gas cap from an auto store for the added peace of mind that some idiot doesn't try to pour anything down my tank.
