I had a cat problem which I took to the dealer. Since I had 50,000 miles on the car, he told me it was covered under warranty. Good thing. They had to replace both pre-cats and the main cat. while doing this, the studs on the Y pipe broke, so they had to replace this as well-at their cost. Moral of story-with an exhaust system as old as yours, expect a lot more than just replacing the cat, and go to a good reputable shop.
