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fishline 01-22-2011 10:17 PM

2004 Wrangler 4.0L Clogged Exhaust?
I have had a total loss of power, RPM's wont go above 3K and Jeep wont go past 35 MPH. I replaced the dual cats back to the "resonator" or whatever that thing is. When I removed the old cats, one of them was completely empty and the other had the honeycomb material visible. Could the material that is missing have clogged up the exhaust somewhere else farther down? Is the "resonator thing" actually another cat converter that could be clogged?

s3nt3nc3d 01-22-2011 10:19 PM

That does sound like a clogged cat...and the resonator thing probably IS the main cat. What you replaced sound more like pre-cats. I've never worked on my exhaust so I can't say for certain...but I don't think the stock exhaust has a resonator.

JDsDream 01-22-2011 10:21 PM

It sounds like you're in limp mode. Is it throwing any codes?

doclouie 01-23-2011 03:55 PM

Had the same problem when my cat got clogged. Remove the bolts before the cat and see if you notice a difference. Once I did that it was loud, but I gained all the power back. I pulled the cat out and it was all broken up and plugged. I got a high flow cat after that and it worked just fine.

TJ Way 01-23-2011 04:49 PM

Just went through an exhaust overall myself. My cat was shot. It rattled INCREDIBLY loud and my power was down as well as my mpg. I was getting maybe 7-8 mpg on the highway.
I replaced my cat with a magnflow direct fit from O'Reily's for $150. After taking off the old cat and looking into it, it was broken into two to three big honeycomb chunks of ceramic that was loose inside. Tipping the old cat would result in small flakes of ceramic flowing out of it. We decided that the muffler was most likely plugged up with ceramic flakes and such, so I put in a Flowmaster Super 44. :D

When it was all said and done, the repair and upgrade makes the Jeep run MUCH MUCH better. It's like night and day. And it sounds like a champ.

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