ehanauer

I've had a rattling sound which has been traced to one of the catalytic converters. My 1995 C4 passed California smog last summer, so I'm good on that until mid 2015. The question is how long can I live with the rattle.

Replacement cats are incredibly expensive, from 2 to 3k. I've got Fister Stage II mufflers, which sound wonderful, but I'm leery of sport cats and their louder sound, as well as California smog tests.

Any suggestions for replacement cats at a decent price? Or shall I just turn up the volume on the stereo?

NYC993

Id go with sport cats. Great sound with fister 2 and cheaper than stock.

NYC993

Oh yea and 15lbs? lighter

C4SJOHN

Are you sure it is the cat? Their are heat shields next to the cat and also next to the mufflers that can be loss or rubbing on something.....

P-daddy

Sport cats!

jerbroo

I don't know what is legal in CA... But, there is a selection of high flow cats out there for far less than 2-3k. Try Jegs

Sent from my iPhone using Rennlist... typos should be expected

race911

IF you've truly determined it's the cat................

THEN, being in CA you're at the mercy of the smog guy, and how vigilant he is. Also consider CA legal cats, the added expense, and that you're not going to get a company to ship a 49 State cat to a CA address. Of course, wholly irrelevant if you source a used cat and (illegally, but who'll know) replace yours.

The gist of it is here, and yeah for OBD 1 cars things are different: http://www.magnaflow.com/02catalytic...california.asp

Ed Hughes

After fully surveying my system recently, this is the first thing I'd look at. One of the 4 receivers for the 1/4 turn bolts snapped Saturday, due to age. A new one is ordered, but I can see where if that happens, it could cause a rattle.

My guess is you don't want Sport Cats, Eric.

TheOtherEric

My money is on the heat shields. Has your cat ever been removed? I ask because perhaps the reinstalled didn't feel like removing the bumper cover to attach the couple hidden screws. This could possibly cause rattling. Or simply corroded heat shields.

Ed Hughes

You can get to the rear heat shield bolts without removing the bumper cover. You will need a 6mm combination wrench.

Rick

If you do decide to replace with OEM cats, I know there are several very low mile cats that folks have laying around when they converted to sport cats or no cats.

M. Schneider

+1
The CAT shield hardware is available and something to re-new
as there's plentiful corrosion at the exhaust shield over time. I'd clean mine up when performing the LPMM muffler DIY. A rattle coming from inside the CAT .... I don't buy it, not at first.

TheOtherEric

We're talking about the quarter-turn fasteners slotted for a screwdriver, right? I can't see how a combination wrench would work there. I really need to know, or else I need to remove my bumper cover to get those stupid fasteners in!!

Ed Hughes

I am talking about the qtr turn bits-2 @ front, 2 @ rear of cat. Truthfully, I can't remember if they are slotted, but mine had a 6mm hex head. Not much room to work there, and I don't have small hands-but I removed and installed my cat recently, when I pulled my motor for the clutch job. I most certainly kept my bumper intact.

JSA993

Eric,
If you find the heat shields are not the cause of the rattle, it could very well be the converter. I had the same issue years ago with my '95. The internal (ceramic?) coating was breaking up. As a temporary fix, I removed the converter and "emptied" the broken pieces. A couple of taps on the ground and back in it went. Lasted probably another 4K before it happened again. I ended up replacing the converter. Good luck getting it sorted.

Jeff

Jeff