Exhaust Rattle

[Chainstretcher]

Hi All,

I have a '98 Wrangler and just recently it's started rattling the exhaust at idle. Not sure exactly where it's coming from but I've checked the hangers and they're fine. Also checked that the exhaust is not banging on the frame or the transmission plate. As near as I can tell, it sounds like the rattle is coming from inside the catalytic converter. Anybody else have a similar problem. The solution so far is to crank up the CD player.

Thanks in advance.

P.S. Will be installing a lift kit, shocks and 31/10.50 tires as soon as they come in, will I be high enough not to hear the rattle? :roll:

[Joker®]

It probably is the cat, they usually crap out after the federally mandated warranty goes out (80,000 miles).

Do you have emissions testing in your area? If not, scrap it and straight pipe it or take a metal rod/angle iron and bust up the honeycomb inside. If you rod it, make sure you get it ALL out of the cat or the rattle will drive you nuts.

[Chainstretcher]

Ya, we gots emissions testing up here so no straight pipe. I passed the emission test easy late October so whatever is rattling isn't hurting anything.

[Joker®]

What you're hearing is the honeycomb breaking up. It will start by blocking the exhaust flow. You'll get excessive back-pressure and your gas mileage will start to suck. My YJ started at 16-18 mpg off the lot, I delt with the rattle until the mpg dropped to 10-12, then I scrapped the cat.

[extexan]

yeah i had the same thing happen on my 95 yj. since you have emissions testing you might try ebay for a new cat. i just cut mine, busted it out, and reinstalled it. i don't know if ebay will have that kind of item, but i think that would be your cheapest avenue. if that doesn't work try a salvage yard. they have to have what u are looking for.
extexan

p.s. i'm jealouse that u r getting a lift and tires. can't wait till i'm able to do the same :)

[LeadFoot]

Good thing cats really don't cost all that much. Be glad its something easy to fix! :)

[oldjeepster]

:lol: I have a 95 wrangler and experienced the same problem, it had 79000 miles on it, and apparently the jeep shop thought I was stupid and wanted to charge for it. I pointed out in the manual that it was covered for 80000 miles. They must have been mad, because now with the new cat on, my exhaust now rattles against the skid plate. :evil:




1 95 yj
1 2002 Blazer
1 2000 Mustang GT
1 91 Blazer

[Mud Girl]

A frien and I had the same problem with our YJ's.

My friend has a YJ about the same age as your's it was the honeycomb in the cat. He just took the cat off broke up the honey come by sticking a pipe in it and braking it up and dumping it out. He put the cat back on and it ran grate and it pased Mass admissions you might want to try it before you go and get a new cat. Worst comes to worst you get a rejection sticker and have 30 days to fix the problem.