I have a 1996 Bonneville, it is a great car but after it sits in my garage for a couple of hours the smell of gasoline is so strong I have to back it out in the driveway. I have replaced the upper intake manifold, fuel filter and had the fuel and the evap inspected. I think it could be a cold weather problem, it happened last year too. No one could figure it out. Snow and ice are coming and I need my car in the garage. The odor is coming from the right rear tire well area, I fill up on the left rear. I did over fill my tank last week, it was past the F on the gauge. Please can anyone help me?
If all the things you say were inspected, then I would look at the fuel injector seals. If there’s an injector seal that’s leaking after the engine is shut off, the gas vapors will sink to the floor and make gas odor appear to be coming from somewhere else on the vehicle.
Take flashlight and inspect all the injectors. And if any have leaking seals, you’ll either find gasoline, or witness stains where gasoline is leaking from an injector.
“The odor is coming from the right rear tire well area”
Have the gas tank inspected,it sounds like it’s leaking.
Do you have a Check Engine light? Your car may or may not have onboard diagnostics to set a specific evaporative leakage code.
Typically if a leak cannot be identified visually, a smoke test machine can be used to inject smoke with a tracer dye. Then a UV black light is used to illuminate the tracer dye at the point of the leak.
Or a fuel line leaking.
Be aware gas will eat asphalt. Guaranteed.