Taylor...If it were me I would probably just replace the muffler and thats it, but a straight piped XJ is cool too. This is probably a very stupid question to ask, but I am assuming you are keeping the CAT on too, right? (I've seen people get away with NO CAT when inspection time comes...I guess it's who you know at the stations.) A friend of mine runs a 97 Cherokee 4.0L Straight Pipe 4"x17" tip with 2 1/4" pipe & no CAT. Then again, he is nuts anyways. If loud is what you are looking for, run this setup.