Replaced my cat with test pipes. Got them off ebay Brand New T-304 Stainless Steel 3"O.D. / 2.75" I.D. Straight Cats With TIG Welding + Cast Iron Flange http://www.stores.ebay.com/delubozparts I got new large exhaust donuts from GT Car parts in Phoenix.623-7802200 $15 each I messed up one o2 sensor in the change out and had to replace it also. Gt Car parts again. NTK 25034 $110 The harness was a direct replacement no problem.