Submitter: Bill (Admin) Date: 2006/7/20 12:50 Views: 403

One day a few yeas ago I was helping inventory Jeep trails in Arizona on some state-owned land in preparation for a trail management plan the land managers were drafting. Since most of the trails didn't have GPS coordinates, the plan was for a group of 4x4 guys to actually drive the trails with GPS devices and then download the data to a map. This worked well and on a nice warm in October I found myself having a great time driving the trails. We split up so we could cover more ground and although usually I suggest against it, I went off alone. My Jeep Wrangler YJ was mostly stock at the time, with 31 inch mud terrains and no lift. A little rubbing is all I suffered...except for ground clearance. Over the years I've been careful to avoid trails and obstacles that I thought might lead to breakage. Breakage is expensive and I'd rather spend the money on upgrades. As I followed what I thought were the directions to a popular OHV trail, I started encountering more difficult terrain than I was anticipating. I thought I could navigate around the big rocks on my own and this worked until I met a particularly large rock followed by what looked like a small dropoff. Up and over I went, nice and slowly, thinking "I'm going to make it! Wohoo" and then BAM! as I cleared the rock with the front tires and then dropped into a large hole. Scraaaaape, griiiind. I was stuck. Good thing I had the thick factory transfer case skid plate! With no lockers, the wheels with the least traction just sat there and spun. Since I was alone I stacked rocks (which I later unstacked) and still couldn't make it work. Fortunately someone else in my group (Stu Olson - thanks!) was within cb distance and we both had GPS so I was easy to find. A few tugs later I was out and rolling. When I assessed the damage I noticed that big old rock left a nice big old dent in my oil pan and my exhaust pipe coming down from the engine. When I got home and took pictures, it became evident to me more than ever before that the YJ collector pipe (as that part of the exhaust pipe is called) was not engineered very well. If your YJ has a 4.0, you'll notice the pipe hanging down lower than anything else except your differentials just waiting for a rock to bash it in.





Furthermore when a rock bashes it in, it may (probably will) lossen the already weak exhaust manifold welding and cause an exhaust leak. When I lifted my YJ I noticed that the front driveshaft also rubbed on the YJ collector pipe. I've never heard anyone mention that, but it happened on mine.



Lifted YJ's don't have as much a worry but that collector pipe hangs down low nonetheless. I discussed the problem online on one of the many Jeep-related BBS's and someone suggestion I try a TJ collector pipe. The TJ pipe is routed in front of the oil pan instead of behind it. Apparently the early TJ 4.0's used the same exhaust manifold and catalytic converter locations and connections so the TJ collector should theoretically bolt up. I acquired a TJ collection from my local Jeep junkyard for $40 and since I don't weld, I had my local muffler shop install it for me. Although the manifold bolted right up (OS sensor is the same, too), the catalytic converter end still had to be welded on mine. This cost me $40. For a grand total of about $80 and some driving around, my Jeep exhaust is no longer a sitting duck. See pics.





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