After 195,xxx miles the cat on my '94 Z28 finally melted into a nice exhaust blocking slag. I took the y-pipe off (single cat) and knocked the metal matrix out, mainly to make sure that was the problem.

Now I've got the typical stinky problems from running no cat, which I don't like, but I do like the extra 2 mpg I've picked up. Frankly I'm surprised that the cat could cause that kind of difference (I've gotten 21-22 mpg ever since I've owned the car), but facts are facts.

Anyway, I'd like to get rid of the stink, and was wondering if anyone could give me their experiences with hi-flow cats vs OEM cats. Engine is totally stock, and will stay that way (it's my DD and has served me well unmodded).

TIA, and have a good one,
Mike

 

a good quality high-flow cat should do just nicely in place of the stocker.

should flow better than stock and keep the stink down.

other option would be to try for a custom dual cat setup...even less restriction.

 

A cheaper option would be to just get a low mileage used stock cat.

 

Hmm, that's an idea that escaped my brain! I think I'll give a call to my local "gently used" parts yard.

Thanks for the idea, and have a good one,
Mike

 

Ebay has them pretty cheap and claim to be high flow but really is hard to say. I found the identical part and 5 claim it to be normal cat and 2 claim high flow. You figure.

 

I bought my rand new high flow magnaflow cat for $55 shipped off an ebay seller (but direct from his website).

It ran me a good chunk to get it installed, but I got screwed over because I wanted the work done on a burning hot sunday afternoon, and they guy jacked the price to discourage me from doing it.
That aside you could probably have a brand new one bought and welding in for less the $120.

http://web.camaross.com/forums/showthread.php?t=530856

I enjoy the deeper tone it gave me!