Project Mithlond EP2: Installing New Exhaust on a Jeep ZJ - Part 1
In 2019 I began the journey of rehabbing my 1993 Jeep Grand Cherokee. After 26 years and 160,000 miles, it had developed a number a problems. While beginning to track down leaks and replace broken parts, I was brought to a decision:
Replace the tires with the stock size
Lift the Jeep and make it into what it was meant to be - an off-roader
I had been considering lifting it, but not seriously, for a couple of years. It was more of a “maybe one-day” type of thing. However, when I had it sitting on jack-stands when I was replacing the rear main seal on the engine, it was clear that my tires needed replacing sooner-than-later. Okay fine, they were nearly BALD.
In Summer 2019 I installed a 3.5-inch lift and new 32-inch tires on the ZJ. But as things go, you change one thing, and it seems that something else needs to be fixed or changed. The original tailpipe was making contact with the new rear track bar, and the old stock exhaust had to go. Not only did this cause every bump to have a loud “thunk” as you drove over it, but overtime it would likely wear a hole in the tailpipe or worse, break something. Faced with this reality (after I had JUST spend >$3K on the lift + tires), I began exploring my options. To add to the situation, after further inspection and a futile attempt to get the tailpipe to bend for clearance while still on the vehicle, I discovered pinholes forming on the muffler which signaled the end of its life. Only after uninstalling the catalytic converter did I fully realize that it also had issues. The substrate within the ‘cat’ had come loose - likely over 10 years ago before I bought the Jeep since it had always rattled while in park.
After a bit of looking at my options, I ended up talking to Kolak Performance & Offroad*, from whom I had actually previously bought my lift kit. I settled on installing their kit for my 4.0L ZJ, which increased the exhaust size from 2 inches to 2.5 inches from the header back - why not upgrade if you have to replace everything anyways? I had the option to buy a new header as well - and still may in the future - but didn’t want to spend the funds at the time (the wallet was still hurting from the lift).
The kit I opted for came with a pre-bent tailpipe, an exhaust hanger, a Flowmaster muffler, a Magnaflow high-flow catalytic converter, a new oxygen sensor, and an exhaust tip. If I got it installed at a shop, they only would have needed to increase the size of the intermediate pipe (between header + catalytic converter) and pretty much slap on the rest. Having someone else do the work, however, is not my style (as you may have guessed). Thus begins Part 1 of this four-part series where I install the new exhaust on my Jeep.
* NOT a sponsor, just a super friendly small business that works on ZJ’s
