well you get used to the noise, jisturm that doesnt work like you think it would, if i were you and i was planningon doing swaps, id just get a raec header,and switch back to the stock when its time, and if you aer getting a cat id spend the dough and get the RT cat, iv got a used one and its in dang good working condition, whileiv heard of new FC cats beginning torust and have other problems