The car is a 91 TBI/Auto. I removed the stock TBI manifolds, Y=Pipe and Cat. I then installed stock TPI Manifolds, Y-Pipe and Cat. The original TBI Cat Back is still installed on the car. Obviously this will not work !! Does anyone know where I could find a flange type adapter/reducer to make these parts join together ?? If someone has the Flange end cut-off from a TPI Cat back,....... I'd be interested !! I would not mind cutting/hacking into the existing TBI cat back, but don't care to alter the TPI Cat. Any/All advise would be great !

that pipe looks nice and rusty, you can pick up a cheap intermediate pipe part number (maremont) 369733

check to see if your local stores can order it, i paid $30 for one, it has that flange, then runs all the way to the back

This probably isn't what you want to hear but if you care about the longevity of that exhaust system, consider having the last few inches of that rusted pipe cut off and a new piece welded in.

The TBI pipe looks a lot worse than it is. The only reason there are any marks in the lip is because I was hittin' it with a claw hammer to knock of any scale/flake that had built in that area.

I'm basically hoping that I can find some type of flanged 'reducer' or flanged "donut" that will allow thes 2 systems to be joined quick and easy. If I get a couple years out of the TBI pipe - that's all I could hope for.

A New IROC intermedaite pipe is about $55 and another $8 would buy a reducer "off the shelf" to the stock TBI muffler ( It's got about 3-4 years left in it. ) If I gotta' weld I'd rather weld where I have better access, so like I said - I'm just hoping to get lucky !

I got a pretty good tip today from a buddy about a buisiness called 'Pipe Dreams" that supplies a lot of muffler shops with specialty stuff. My fingers are crossed !! Please keep the ideas coming !

I did that a couple years ago, I just welded it. Although, my intermediate pipe was much more solid (no rust at all) and might have been larger. It was a single Flowmaster setup that necked down to 2.5 inches near the cat. The cat was the 3 incher like you have. It is still holding up fine.

I had a local shop weld the proper sized flange on the TBI Cat back. The "adapter" that was added was pretty long and ends in about the middle of a normal Intermediate pipe. ( original rusty TBI flange end was cut off completely.) Total cost was $75.

After that connection was made I found that the passenger side manifold to Y-pipe had a leak. It wasn't noticable when driving around with the exhaust ending at the Cat ( I love doing that ! ) but once the system was connected the famous "tick" sound of an exhuast exhaust leak was noticed right away. It was nice today so I was under the car re-adjusting the spacer between the Y and the manifold and everything is sealed up nice and tight now !

Thanx for all the input guys !