Hey man just wanted to ask you, if custom welding an aftermarket cat onto the weapon r will diminish the weapon r's gains?? Because I am quite worried about running a test pipe, where they are pretty strict. Im currently deciding on either Comptech header with RT cat....which will rattle like crazy (I have an Auto) or the Weapon R with custom cat welding. One more question is, will doing the custom cat weld to the weapon r give me lots of hassle in terms of installation (O2 sensor etc etc...)Thank you very much for your help!!!