On my 87 IROC, I've got a Borla exhaust (p/n 14888) and stock manifolds. My cat needs to be replaced, and I plan on buying a high flow cat. My question is this...what are some of the decent high flows out there that are direct fits? I found a Catco that has 3inch inlets and outlets, but I'd rather not have to deal with taking the car to an exhaust shop and having adapters welded up.

So if anybody has any experiance with direct fit high flow cats, drop me some info please.

Thanks.

 

Thats is about as a direct fit as you are gone to find. As long as its not the unversal one.

 

Fluffy, when you say, "I found a Catco that has 3inch inlets and outlets, but I'd rather not have to deal with taking the car to an exhaust shop and having adapters welded up," I assume you mean you found a universal 3" in/out. Don't do it.

You didn't say boo about what your combo is, but I'll assume TPI. If so, http://store.summitracing.com/defaul...9118&x=17&y=10 is a direct fit.

If in fact you have an LG4, don't get a direct-fit cat. Get the one above and adapt your exhaust to it (not the other way around). Then, you'll at least have the cat when you fix the rest of your exhaust.

 

five7kid, I do indeed have a TPI...and you found a part I'd not been able to find (though I didn't look very long, I could only find dual cat setups as well as 305 cats)

Thank you very much!

Next question...In the stock cat, which is still installed on the car, how does the outlet attach to the rest of the exhaust pipe? Currently you can jiggle the pipe to the muffler around inside of the bracket on the trailing edge of the cat, which the state of NJ seems to think is an "exhaust leak" Just trying to figure out how I'll be attaching the cat.

 

The cat outlet is a ball flange, with the "clamp" being part of the intermediate pipe behind the cat. Two bolts go through the I-pipe flange and thread into the cat flange.

It is possible to have some relative movement between the cat & I-pipe without it being a "leak" possibility. Just because I said it, though, doesn't mean the State of NJ will accept that at face value...

 

Thanks for the help, trying to remember back to the last time I had it up on a lift, I don't think there were any bolts in the clamp. Maybe i'll try using some.