Today I replaced my complete exhaust system. I am in California and the catalytic converter cost me $509 plus tax, ouch. Last weekend my muffler blew a big gash (backfire on the highway I suspect) and, although I welded a piece of sheet metal over that that closed it up, the car also had suffered a ruptured fuel pressure regulator that caused a few gallons of raw fuel to wash straight into the exhaust system and burned up there with huge clouds of smoke - according to a mechanic buddy who helped me diagnose and fix it, this likely destroyed the cat. So rather than chancing it at the annual smog check, I decided to just replace the whole system. The old one was welded together so had to cut it in two sections to get it out, and installed a Magnaflow dual cat, California/CARB appropriate, without welding but with the proper gaskets, spring bolts etc. The muffler and tailpipes were only about $65 together. Anyway, now the system is a whole lot quieter, and although the truck was running really well and strong (with its 230,000 miles), it seems even peppier now. So I am happy I bit the bullet, and will feel a whole lot more confident when I pull up to the SMOG station next month.