1999 Subaru Forester smells like gas

1999 Subaru Forester with gas odors. I have replaced two vent lines and tightened all clamps. There is no evidence of external raw fuel leak. Seems most noticeable after it’s been sitting awhile or when low on gas. Previous owner cut hole in back floor panel (it’s ugly) to access lines and fuel pump. Fuel pump gasket was replaced as well. Smell seems to be coming from there but spreads into whole cab. Ideas?