Anything to be done about a rattling catalytic?

My '98 Cherokee just had its cat replaced yesterday. There's no cheap solution. You'll have to replace it. Mine had a honeycomb like structure inside which broke into bits. Parts of it also went into the muffler.

The muffler, cat, and downstream O2 sensor were all replaced since the muffler was also badly rusted out.

I have just shy of 99K miles on mine so it was quite a bit out of warranty. I'm impressed that it lasted _that_ long...

-John

Yup, I agree here. It needs replacing. I wish I didn't let mine go as long as I did in my 94- I drove way too long with that 'rattle', and it ended up taking my muffler out in the process. No cheap way to do it, either.

coop

Even though it just sounds like a metal heat shield or something rattling? It doesn't sound like the internal honeycomb stuff.

I'm out of the 80K warranty...

-jeff

Did you go poking around there? I don't know if it is true of your cat or not, but I've seen sheet metal heat shields tacked onto the bottoms to reduce the chance of starting grass fires. After a while they rust, loosen up and make a tinny rattle. If that's what you've got and it is loose enough to rattle, it is probably loose enough to pull off with your bare hands.

Check for rocks between cat and shield Tookie - Denham Springs, LA

I was hoping that mine was a heat shield, too. I'm not saying that your's isn't -- anything is possible. You'll have to crawl under there and look. :)

My shield was tight. I couldn't get any noise out of it at all unless the engine was running. Wiggling it with the engine off didn't do anything. The only time I got the noise was when the engine was idling slowly -- like when just pulling away from a dead stop.

-John

Fyi,

When I bought my my jeep last month it had a rattle that sounded like the heat shield. When you stopped the engine it went "tonk tonk tonk", just like something vibrating. Part of the purchase agreement was to "fix the rattle".

Got refered to a muffler shop. Cat had come apart, and the guy was expecting it. He said he's many jeeps of this age with their cat's disintegrating. It's a 1995 jeep cherokee, 110k miles. For me, it was fixed for free atleast. :)

-Andrew

Same with my 97 TJ, nothing loose but rattle when I take off from stop. Really annoying.

Tom

Redge Egder did pass the time by typing:

Yes, before it causes more problems.

In the US that's part of the emissions system and should be covered up to 80,000 miles. Check the dealer. Even if your out of warranty they might work a deal with you. Also check local muffler shops some places will install a new cat for reasonable prices. Shop around.