I already have an aftermarket cat, is it one piece, or is the cat separate? if it is one piece then im sry for wasting your time but i am not interested simply because i do not want to pay money for something i already have/dont need, unless i could attach it to my downpipe which i believe has the cat attached although i am not certain (sry relatively new at this) and you wouldnt charge for the cat. If it isnt one piece then if you would be willing to separate the cat, I would buy the rest. Once again, im fairly new at this so i could be mistaken as to how all this is pieced together, but let me know. thanks