I have a 2007.5 3500 6.7 with a manuel tranny......my question is there anybody that has eliminated there muffler, cat, and dpf on a 6.7L . .? if so what were the gains ? any problems..? any problems with the computer..? also i live in california so i know im not supposed to remove any of the smog crap but ....for the sake of conversation....of course.