i have a stock 87 TA. i just bought a dyno max cat back. it has the 3" pipe going to the muffler then dual 2.5" going out. the stock pipe is 2.25". then the cat. it has a 2.25" going in and 2.25" going out. i was going to have this shop put it on. and they said they couldn't becasue it would sound like crap. the told me to buy a new cat. the cat is going to be around 80 bucks. i dont want the cat tho. plus in about 2 month's ill have a new 350 with headers and the y pipe. i hardly dought its going to be 2.25" off the y pipe. there for if i got this cat with a 2.25 in and a 3" going out it wouldnt work because going in from the y pipe it wouldnt be right again. i just want the cat back on for the least amount of money. what do you guys suggest to do... get a pipe to stick in he cat with a 3" outlet or what? im totally lost and need help b/c my car sounds like crap running the exhaust straight out of the cat.

 

i have the same problem as you do. i got the same catback as you with the stock cat. what i am going to do is just run a straight pipe for the cat and hook it up to my y-pipe like that. i sure hopes that work out good for me because i'm not buying a new cat..........

 

You don't need a new cat. Just have the idiots bolt it on till you get headers, THEN you get a nice 3" cat.

 

They said it would sound like crap, they're morons. I had this guy at an exhaust shop tell me this once, it's not worth the trouble to run 3", it's too difficult to go over the rear end. I'd say it was very worth it and now my cat-back doesn't bottom out over speed bumps like my stock pipe. And this all was with adding a cat as opposed to having none in the first place.