Hello, I have a 7.3 excursion. Stock exhaust but the cat has been removed. My father has a 7.3 same year and we are both running the same tune. His will black out the road and mine is fairly clean burning with a lite haze at wot. The only thing done to his is a bigger fuel pump a intake kit and a 5 inch exhaust. My truck is completely stock besides the tune and cat being removed. Is what is done to his truck and the fact mine has a muffler enough to make it not smoke at all?