Cat--Sounds like loose junk inside

[Silver 99 Camaro]

My cat seems fine, it doesn't make noise and the car runs fine. There is a very slight low pitch rattle that happens right from starting from a stop. So I banged around on the exhaust looking for the usual suspects, y-pipe rattle and heat shields. All were fine, but I could here a very slight rattling of loose junk (sandy sounding) from the inside of the converter. I've had that on other cars, although they were much older than the Camaro. Has anybody had that, and it turned into a problem? I know the cat is covered for 7 years and 70,000 miles, and I am at 65,000, so I want to take care of it right away if I need to. Any info would be appreciated, especially since I know the dealer will charge me a ton to get it checked out.

[Yaba3800]

if its rattleing that means your cat needs to be replaced as far as emissions go

[JCamaro3800]

Yaba 3800's right. If your cat is rattling then some or all of the ceramic mesh inside is broken. This happend to me when I took mine off. Mine was totally shot though because some raw fuel from a misfiring cyliner got down into it and clogged it up.

[Silver 99 Camaro]

So the light rattle I get when I first step on the gas could be the cat. Has anybody had a cat replaced under the federal emissions warranty? I hear for mine it's 8 years/80,000 miles.

[tinman_aaa]

I just noticed this same problem a couple of days ago! It only gets raspy as I accelerate and as I was looking in my exhaust tips I saw pieces of metal. So it looks like I need to replace my cat :( . Maybe this is a good excuse to get a high-flow one.

[casketcrewchick]

I think my catco is dead... I heard some stuff inside bouncing around... had it for a year. piece of ****. Anyways i just got my exhaust welded up all nice and now it looks like we have to get a new cat. :(

[Silver 99 Camaro]

Ok, I know it's probably dying. I don't want a high flow cat, I want a free one from GM since it is still under the federal warranty and a good muffler shop won't touch it while under that warranty anyway.

Has anybody gone through the dealer to get it replaced free under the 8 year/80,000 mile warranty and what did you have to do to get them to honor it?