Well if you have a 3" exhaust with a relatively new cat then I'd say the cat probably isn't your problem. Drivability wise, it's not something that happens over night. Basically, the same symtoms as a restrictive exhaust (slow spoolup etc). It's usually caused from cars that have a tendency to burn oil which causes the cat to fail. An easy way to check is just to run a test pipe to see if it fixes it.



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91 Talon TSI FWD