dude stop putting some of your post as part of the title, i keeping thinking ur a big retard cuz ur sentences dont make any sense

and no just a muffler will not add any significant HP, not even cat backs...if your just looking for the sound just buy an axle back. tell him 50 bucks for that muffler if u really want it.

*I wanted some back pressure on my car so all i had was a header and with an axle back.... stock piping - BACK PRESSURE CAN BE GOOD *