General Maintenance & Repairs - Blown cats common?

Yesterday my SS started making a HORRIBLE rattling noise. It sounded like a metal on metal clank. At first I thought it had to be internal engine damage since I had gotten on her a couple times on the drive home. Well, I put her up in the air and the noise is definitely coming from the passenger side cat. Is it common for the cats to go bad like this with only 34,000 miles?

Well I know 3 people who had to have their's replaced free under the federal emissions warranty - two driver's side (P0420) and one passenger side (P0430). All threw a code before rattling though.

no codes yet :confused:

Yesterday my SS started making a HORRIBLE rattling noise. It sounded like a metal on metal clank. At first I thought it had to be internal engine damage since I had gotten on her a couple times on the drive home. Well, I put her up in the air and the noise is definitely coming from the passenger side cat. Is it common for the cats to go bad like this with only 34,000 miles?

Mine went out at 120,000. You can take it to the dealership and get it replaced under warranty. The reason the usually go out if the car is running to lean. You might want to look into that possibilty.

Did yours set any codes or make any rattling noises?

No catalyst low efficiency code is a mystery, know anyone with a scanner so you can see what the rear 02's are reading? Maybe it's not completely gone yet and still within parameters? Another thing to look at is the appearance of the cat - does it appear damaged or discolored from overheating? I do know the dealerships wanted to see the code before replacing the cat.

It's not throwing a code, nore does it appear damaged, but all you have to do is start the car and listen. It's very apparent, even from a distance, that something is broken. Once you get under the car, it's pretty easy to narrow it down to the cat. Even though I won't even have cats as soon as I get around to putting the headers/ORY on, I still made an appointment with the dealership to have it fixed.

Had the cats go on both cars. The WS6 started throwing a code for a bad cat. The Firehawk started doing the whole rattling thing like yours. I forget what mileage they went bad on both at but it was in the 50K-70K range. We could have had it covered under emissions warrenty at the dealer but we didn't feel like bothering with the dealer. Didn't have the money for headers so we just gutted the cats. We already had tuning software so we took care of the codes.

I went thru 3 cats in 60K miles, said screw it and gutted them after getting my fourth code for a bad cat. No problems since! :jest: