I currently have a 00 xj with 211k......its runs good but at that mileage i was thinking of swapping in a motor with less miles, also i dont want the coil pack would rather have plugs and wires. my question is i have a cali emmisions xj with 3 cats, would i need the same year exhaust as the motor i would be putting in, i.e 99 engine and exhaust? im on a very limited budget and would gladly take any advice, know how and or detailed description.....thanks guys

 

Well the best advice I can give at this point is to run it til it dies. Why waste a potential 100k more miles?

Otherwise, look for a 99 and lower as to avoid the 331 cast heads.

 

At that mileage the 4.0 is supposed to be just getting broke in nicely




Just keep up your cooling system and don't let it overheat

 

^Yup what he said^


During that time you have time to shop around for a parts XJ with the engine you want, be sure that it has the computer with it also along with the exhaust.

 

It is against the forum rules to talk about removing catalytic converters, so we're all limited in what we can tell you regarding that. Keep in mind that your Jeep's computer is expecting data from the four O2 sensors and other emissions equipment on your truck, so it wouldn't be as easy as you might think. It would be a lot easier and more sane just to keep the existing exhaust, emissions equipment and computer. The 2000 exhaust manifold will mate up with the older 0630 head, although some people get exhaust leaks and need to run an adapter plate for the difference in the size of the exhaust ports.

The computer is also set up for the 2000-2001 waste-spark ignition that uses either the coil rail or a Viper coil mod with plug wires. If you're talking about going to a distributor instead, 1) you're nuts because the waste-spark ignition is a superior system that provides about the hottest spark you're going to get with the fewest parts and therefore fewer things to go wrong, and 2) you would need to swap in the older Jeep's computer and wiring harness to handle the inferior ignition system. Obviously swapping in an older computer has emissions implications we can't talk about. Regardless, I'm not sure why you would want to swap in a more complicated system for a downgrade in performance when you can just adapt the existing computer, ignition and wiring harness to the older engine.

 

The computer and exhaust from another XJ 99 and earlier will work fine also and do away with all of those items, but still preform as it should.