2004 Ford Expedition 5.4 gas smell

Could we get a bit more detail. Does this happen all the time, after driving for a while, after a fill up, worse when the tank is near empty, smell just outside the car or can you smell it inside also?

It could be a lot of things (filler neck, gas cap, charcoal canister, purge solenoid). I would give it a good visual inspection to see if there is anything obvious. Otherwise, a smoke test might give you a clue.