I have a 1989 Iroc, I have been doin some research and i was wondering if the cat is bolt on or weld on? And can I do it myself?

 

My 85 is bolt on. Look under the car and you will be able to tell. Post a picture if you are unsure.

 

I believe the front is welded to the y-pipe, and the back is bolted to the rest of the exhaust. Its best to take it to an exhaust shop and have them replace it with aftermarket one from Magnaflow, Catco, or Random Tech.

 

FWIW, the cat in my '87 IROC is slip-on to the y-pipe, and bolt-on to the rest of the exhaust. I'm in the process of replacing the OEM cat.

If you have an air injection tube at the cat, it's pain to get this slip-on connection separated. I ended up cutting off the tube on the old cat with a Dremel and working the cut off end out of the air tube with a hammer and locking pliers. I'm seriously considering using a stainless steel compression union to connect the tube to the new cat in order to eliminate the slip fit for next time I need to do any exhaust work.

Also, if you go with a Catco replacement (P/N 9118) you'll need to get some extra nuts. Unlike the OEM cat where the holes in the flange for the pipe connection and the mount are threaded, Catco just has un-threaded thru holes. You might need longer bolts to accomodate the thicker Catco flange and extra thread length for the nuts.

 

Im going to order the Magnaflow high flow converter, Does any body know what the in/out is on the 89 Iroc?

 

All TBI exhausts use the 2 1/4" cat and exhaust. You can replace it with another 2 1/4" cat, or get your muffler shop to upgrade the rest of your exhaust to 2 1/2" or 3" specs.

 

Okay so I got my magnaflow cat in the mail today, when i matched the length of the new one to the old one there was a good 4-7 inch difference between them,the stock is longer. Should this be a problem when i take it to the exhaust shop tommorow? Or will it work?

 

Well so okay I think the muffler shop can make an extension pipe easy enough to take up the missing length.

 

I just got my car back from the muffler shop, and I have to say im very satisfied with this cat converter. My car sounds a whole lot better especially when i start it.I had no clue that a converter could improve sound quality that much. But I do have one question, Why is my check engine light still coming on? could it be my timing?

 

What code is it? We need that information before we can tell you what the problem is.

 

First guess would be the shop unplugged the O2 sensor while working on the exhaust and forgot to plug it back in. Needs to be fixed soon if so, if the fuel mixture gets out of whack it will mess up the new cat.