Also, check the seal on the fuel pump... I was detecting a fuel odor when driving the car and it turned out that the fuel pump had lost it's seal due to corrosion on the tank sealing surface. I decided to drop the tank, clean everthing up really good, replace the seal, paint and reundercoat as necessary but that was only becasue I wasn't sure what the problem was at the time. You should be able to clean up the sealing surface and replace the pump gasket all from the access panel, w/out dropping the tank.