Hey guys, I've got this new noise coming from under the Jeep.

2007 JKU Rubi, 4" lift with 35s, manual transmission.

Right before my shift point, between 2500-3000 RPMs I can hear this rattling/squeaking noise. Clutch disc, transmission, clutch?

Anyone experienced this noise before?

 

Wouldn't happen to be a burnt out catalytic converter, would it? Had the same kinda thing on my Lincoln. Just a thought

 

Would there be any other signs that it would be a cat? Never thought about that ...

 

Tap them with the handle end of a hammer. When I did that to mine, you could hear the honeycomb inside banging on the can. Once it gets bad enough, the check engine light will come on.

 

So I got a P0420 code. So I'm thinking it must be the cat. No abnormal sound when I tap it with a hammer, but I can't imagine what else it would be.

 

Yeah, sounds like that's gong to be your problem. Sorry to hear that my man.

 

Hi Zack. I'm currently running the same P0420 code. Did you end up replacing that cat to clear the code? If so, about how much did it run you (if you don't mind me asking).

Thanks,
-AL

 

Also check the welds on the heat shield on the exhaust right under the transmission. They make one heck of a sound at about 2000-2500 rpm when one breaks. Easy fix but if your throwing cat codes it might be time to replace

 

And if it is the catalytic converter you need to find out WHY it burned out. Running very rich can pump unburned gas into the cat and it will burn out. I went through three of them on a Ford work truck. Company paid for the repairs but I was still PO'd that shop didn't find out why they were burning up so quickly. Finally traded the truck for a new one.

 

Aren't cats part of the emission system and under warranty for about 8 years? I would check with the dealer.

Edit: Quick search on the Jeep manual:
B. Parts Covered for 8 years or 80,000 miles
If your vehicle has one of the following parts, this
Federal Emission Warranty covers that part for a
period of 8 years or 80,000 miles, whichever occurs
first.
These limits are counted from the time when your
Basic Warranty begins under 2.1(D). The covered
parts are:
• catalytic converter; and
• powertrain control module.