Hey, I want to build up a new catalyst, because the old one has just been waved through the last AU, and now a leak has arisen between the cat and the exhaust pipe. To do this, I need one of the two catalysts, according to the Rockauto as well as Walker Exhausts:Walker 15735 EPA CompliantWalker 81174 C.A.R.B. Compliant Which cat should I buy now? According to stickers in the bonnet, the vehicle is Federal Emissions Compliant. with the EPA Kat at the AU will fall on the muzzle. On the website of Walker only the C.A.R.B. Kat is spoken of “the right mixture” of metals. That makes me a bit stubborn. Does any of you have experience? And do I need more small parts, such as seals, or really only this flange? Thanks in advance and LG, Denis