We have been noticing a raw gas smell from the car after it has been running a while. Noticeable inside the car when stopped for traffic light. No spot on garage floor and no smell in the morning after car is in garage overnight. Have raised the hood and can get a faint whiff on left side of engine. Mechanic friend who works on domestic cars says maybe a faulty "O" ring or fitting in fuel injector system. Anyone else had this happen??