I ordered an exhaust system for a '99 - '04 WJ with Flowmaster Super 44 muffler. The company is now telling me it would need modification to work on a 4.0 as it's originally designed for a 4.7... any idea what modification it needs? My Jeep is an '04 WJ 4.0 2WD

 

Modifications to them is cutting pipes, changing sizes, or adding pipe sections to get it to fit. No big deal. I put a muffler for a 97 ZJ on my 2000 WJ because I wanted just a little more sound and I had to add a 6" long pipe to make it fit.

 

How much you think a shop will charge to modify?

I've done my own exhausts before, but not ones that require modifications.

Thanks!

 

If you're talking about a complete system designed for the 4.7, it ain't gonna work on a 4.0. The headpipes and cats are different. If you're only talking about the muffler, that's a different story. Only the length is different.

 

Like Dave said, if it's a cat back my local shop charged me $150 to install a stainless steel Megaflow exhaust. They needed to add a 10 inch section of pipe between the cat and muffler. (previous owner cut stuff)

Now that local shop did not install it correctly. They used a non stainless piece of 10 inch pipe which will rust out here in the Northeast. Pointless. And they used clamps instead of welding and it whistles upon hard acceleration. I had asked them about welding it, they said nah, the clamps are fine. Wrong. They knew it whistled as they tried to put some exhaust putty around the connection where it was whistling. When I called about the whistling, they said it was a weep hole in the muffler and it would rust over. WTF. That muffler doesn't even have a weep hole. Obviously never going there again.

I found another shop that will put a 10" piece of stainless and weld everything correctly for another $150. Ended being a very expensive exhaust.

 

I'm just gonna re-sell it and get one for the 4.0 then, it sounds like.