Ok guys, here it is. My Dad drives the GSL-SE, and for the past few months, shes been going downhill quite drastically as far as her running condition...Shes been idling really rough, she still gets up and goes just fine, but she idles ROUGH. Anyway, if your outside the car when its running, you can hear an exhaust leak coming from the pre-cat area on the pipe. It kinda sounds like its coming from behind the front right wheel, but further down from the header I guess...More under the dash area...Anyway, he says that its been smelling like rotten eggs, and I just read on here that cats tend to smell like that after they die, or are dying (not that ive been around many dead cats ). Anyway, what would be the very most cost effective thing to do, and could the rough running state be brought on by the bad cat and/or exhaust leak? No emissions testing to worry about where he is, but I dont want to mod the car that much at all (ie - remove as little emissions equip as possible). So what do you think I should do?

~T.J.

 

Gutting the cats is free, but I wouldn't leave it that way. Gutted cats tend to leak and you lose exhaust velocity with a gutted main cat.

But it will get you by.

 

Since emissions aren't a problem, go get a resonated midpipe. rx7.com sells one that's alot like my Bonez converter system except minus the cat.

I had similar symptoms (including 20 MPH less on the top end of 4th) before I replaced my cats. When I took the stock cat's off, they were totally hosed, most of the material fell right out the pre-cat when it hit the floor.

--matt
85 GSL-SE

 

anyone gut a thermal reactor ('79)? or will i get a meltdown and radiation poisoning?

 

Ok...So if I eventually wanted full aftermarket exhaust, and I need to start with getting the cats fixed/replaced/removed whatever...what should I do? I want headers and a muffler eventually, but I want to replace this cat problem first. My concern is that if I buy something to fix the cat, and then buy a header and/or a muffler it wont all fit anymore...Or should I just save some pennies and buy it all at once from say RB or something?

~T.J.

 

You should be able to buy one at a time... hell, thats what im doin.

 

I would price out replace the exhaust manifold and the cat with a RB header and presilencer. Just use your existing mufflers for now. That will save some $$$$. It may be just as cheap to replace your cat with the header setup as trying to replace the cat.

JEREMY:
There is nothing to gut in the thermal reactor. If you have a thermal reactor then you have a heat exchanger instead of a cat. See above info, it applies to you also.
I replaced mine on my 80 with the RB setup.
I love it.
hanman

 

Why don't you gut them? Then hang them out on a clothes line to dry?

 

well see, i have no money so buying a header isn't even in my list till way down the road. i'm looking for simple free power adders while i try to find a gas tank so i can actually run the car.

 

I made mine for my 85, i just cut the end of the precats and made a pipe to fit between them... I might no be needing it anymore... So when I get everything said and done ill probally sell it. It will ONLY bypass the first 2 smaller cats the other cat is a simple cut both ends off and weld a pipe between them

 

When I was cleaning under my car, I went to shake one of the pre-cats (just to see if everything was snug) and the top came off completely! Now it's kind of loud, but I like it, especially after a good rev!!

 

ive been riding with a clogged cat for almost a year......