I have a 03 with a UPR off-road x-pipe coupled to a magnaflow catback and am thinking of putting on some longtubes with either a shorti pro-chamber or another offroad x-pipe and am wondering how different it will sound with another x-pipe and headers. it sounds pretty good now except when you are decelerating in gear, it makes a funny noise you can only hear from behind it, kind of a vacuum/sucking sound. just want to know how headers will change the sound, thats all. thanks