Exhaust leak at manifold and cat down pipe

UnlimitedFun

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Original poster
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May 29, 2024
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Location
Attleboro, MA
I've had an exhaust leak since i got my jeep a few months back. 2006 Unlimited with 4.0. I finally tracked it down and found that the the flange right above the cats that connects to the manifold is loose. I can push up on the down pipe and see movement. I tried to access the four bolts but couldn't find a combo that worked. The cats are fat plus are close to the flange making the angels tough.

I'm assuming this has to be possible with remove the intake and accessing from above. Any suggestions?
 
Ah the weekly downpipe bolt thread

You just need to find a combination of tools that lets you get in there. I certainly wouldn't take the intake off, I'm not sure that would even allow you better access anyway.

These Sunex Sockets along with a combo of various length 3/8 extensions allowed me to get to all the bolts when I still had my factory downpipe on my '05. But, it seems like different years may have different sized bolt heads and I just installed a Flowmaster downpipe and the Sunex sockets no longer allow me the clearance I need, so it's not guaranteed. But I'm still able to reach up there from below with crescent wrenches and get to the bolts. Removing the fender/fender liner (It's been so long since I had OEM fenders I don't remember) is an approach a lot of people take. The bolts thread into these sort of captive nut clips, I don't remember what they're called... regardless, you don't need to hold a nut or anything on the top side.

It can also help to get them really tight, warm up the Jeep a bit, and tighten them again.
 
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I have sockets like those sunex mentioned above, but i guess they are too fat or the cat is too fat for them to fit around. I was able to find a combo that worked with a short 3/8" wobble extension. Seems the nut on the other side isn't welded to the manifold it's using something like i have pictured here. I applied significant torque in alternating directions but didn't budge. I'm going to break those tabs off before anything. Who thought this design was a good idea?

I'm thinking next step might be to take fenders off for better access and apply heat.


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