My car has been occasionally experiencing what I believe is a backfire when the clutch is depressed changing gears. This isn't the slight muffled popping noise i noticed when i got my exhaust, it actually sounds like a cap gun. I feel like uncle buck. I was thinking it could be the NGK plugs not completely burning the fuel and the gases combusting in the exhaust. Maybe I should go back to the motorcraft. I have headers, y-pipe, and dual exhaust. I have the stock cat on. Suggestions of what to do or possible leads. I don't expect the slight poping to go away, all research points its a common thing, but the occasional cap gun sound doesn't coordinate to anything I've seen in the archive. Thanks