Hi, I'm Robert and have a 92 RS Camaro w/ the 5.0 TBI. I just replaced my catback, with a Dynomax, in order to get rid of a serious vibration rattle that my shot, stock muffler was causing. Now that I finish installing that, not too hard even with a 1-piece I-pipe, I have found that I have an additional vibration rattle before the cat. I would like to know what my options are pricewise, I must retain my cat. I know I have a single cat and I'm not sure what there is out there that will bolt on. I am trying to not spend too much money(student), but I don't want anything that's trash. I think I am capable of doing the install myself and would prefer not to pay for custom work. I am pretty sure the y-pipe is gone too. Also does anyone make a replacement cat that will bolt right on? Thanks for your replies.

 

If you're getting headers, you really don't want the type that bolt right to your car. Why? Because the TBI exhaust was restrictive, and putting on headers & cat made for TBI will retain the restrictions.

The best single cat systems are those intended for '86-'91 TPI single cat. SLP, Edelbrock, Hooker, and Hedman all make headers with a y-pipe that goes to a 3" slip-fit cat. You can then buy a direct-fit cat for the same application and have a great-flowing system that will bolt right to your engine and fit in the chassis just fine.

The unfortunate part is that you already purchased and installed a cat-back, because most likely you got it for your TBI car. The best approach would have been to get the entire exhaust for the application above. But, you can probably have the cat-back modified to fit the TPI parts, so if in the future you do additional performance mods, you can put a TPI-type cat-back on as well.

Others may argue to the contrary, but for the time being, I'd say this approach will eliminate the initial restriction of factory TBI manifolds, y-pipe, and cat, and give you adequate performance for your car as it is now. The TBI cat-back won't hurt you as much as you would be if it all was the other way around (TBI y-pipe & cat w/TPI cat-back).

 

i would second what five7kid said. just get a reducer so you can use the stock cat and cat back and get the tpi headers + y-pipe. taht way in the future itll be there for ya. I wish i did. I bought headers + y-pipe for my 305 And jsut slapped em on my 200 HP 350 when i decided to get a crate instead of fix the old 305. Lemme tell you that stock exaust was just good enough and no more. Engine put out around 170 hp witht eh stock exaust system and muffler. Dumped it and put a flowmaster in its place and the power output jumped to around 195 hp.