I have a 1997 4.6l f150. fight now i have a single in dual out flowmaster delta 40. how would it sound if i took out the muffler and replaced it with a Y-pipe? would it help/hurt anything? thanks

 

It won't really hurt anything, but you'll probably lose too much back pressure which will result in lose of HP and Torque. I don't recommend it, it doesn't make it sound very much louder if that's what your going for. I have the same muffler on my truck as you do. I think it sounds better with the muffler. If your looking for louder, get rid of the Four Catalytic Converters and put on two high flow cats and keep the flowmaster. Maybe even switch the muffler to there original 40 series, not the delta flow. Still not much of a difference between the two though.

 

Although, Mine is a 5.4L