blkcheerio

OK. So finally after what seems like forever, getting to build the Jeep. But on a very right budget. Got the lift on and everything and I'm real excited for our Wellsville trip labor day weekend. But I'm not sure about the exhaust. I need some input, so I can make a solid decision. Right now. The jeeps sits with the exhaust pipe just before the cat resting on the tranny cossmemeber. Then a short pipe. Then muffler. That's it. All just sitting there. Pretty sure the cat is wasted and the o2 sensor wires a ripped out. Can I just cut it off and wheel it? Its not going back on the street. Its only going to be a wheeler. Is the o2 sensor actually important there? Do I need a cat and muffler to create back pressure? Just a cat? Just a muffler? A friend of mine had an 87older that we just hacked off. But I understand that a 98 is pretty different when it comes to the computer. I've also read that I need that o2 sensor because without it I'm losing quite a bit of torque. Facts? Myths? Please help and remember. As cheap as possible... thanks fellas

Lowrange2

Just attach it like you have it and wheel.

Ya don't want it flopping around back there and crack your manifold.

cf1k1

Just a heads up, talking about catless vehicles is against forum rules. However, to answer your question, hypothetically speaking, you can't do it unless you weld a bung hole for that o2 sensor. The back pressure theory was a myth disproven a while ago. What you need is something called "scavenging" or I might have the wrong term for it. I have a 2001 and I don't have an o2 sensor there. But, no, you don't need back pressure however it can be done.

Outlaw Star

Correct on the scavenging and cat removal. As for the O2, you will not lose TQ but your XJ will run very poorly due to it dumping fuel. This will also cause damage to your motor. You can buy a high flow cat for under 100 bucks.

565matt

2001's dont have an O2 before the muffler but you do have 4 on the manifolds with 2 seperate cats.. The 98 has a cat down by the mufler with the downstream O2

cf1k1

That's what I said lol. I had three cats.

Lowrange2

Meow.

blkcheerio

first trip today... when she was a DD she ran fine. crawling through the creek today... she almost didnt make it out. loading up on fuel. big time. cat goes back on and have to figure out the 02 sensor. the wires were ripped out of the plug from the drive shaft. wires out of 02 sensor are 2 white, black and green. vehicle side is black, green/white, brown/yellow and tan/white. i hope im right... trying to remember here. ive done some searching and having a hard time finding anything on what wires go to what. anyone know? big trip labor day. after building this thing for a month, full of headaches... id hate to miss this trip