Hi Guys can anyone help...I think I have a 02 sensor fault as my engine management light comes on now and then...and over the last couple of weeks one of the cats has started chattering ( the expensive one on the left of the car)...can anyone tell me is the standard XFire exhaust Stainless steel and can I buy a replace ment cat and have it welded in ..and any recommended replacements..I am in the uk and we have strong emission rules...Thanks Chaps.