I have finished swapping a '98 XJ 4.0L engine, tranny, and t.case into my '89 YJ (it was a 2.5L). I wrote an article covering the swap for anyone who is interested. Ten years newer technology and a bigger engine are sweet!
-Brent Bogrees '89 YJ 4.0L w/ 33" BFG MT's '94 XJ 4.0L w/ 31" BFG AT's
Excellent documentation! The only disappointment I saw was the mileage on the 98 4.0 (157K).
Looks like you have a nice shop and a cool dad.
Nice article.
BTW, where did you put the O2 Sensor?
Thanks,
bill
Good job on the site and the jeep!
Thanks. My Dad has been instrumental in teaching me the vast realm of auto mechanics for the past 18 months. It is crazy how much I have learned and accomplished with my Jeep. It is an empowering feeling to be driving something you know so well.
For the O2 sensors, I bought an exhaust pipe (manifold to cat) for a
4.0L YJ, so I just plugged the upstream O2 sensor in that pipe. The downstream O2 sensor is supposed to plug into the cat, but the YJ cat doesn't have an O2 hole like the '98 XJ. The only thing the downstream O2 sensor does (to my knowledge) is detect if your cat is bad or not by measuring the difference between the upstream and downstream O2's. So I just plugged the wires in for the downstream O2, and tied the sensor out of the way. This way, I don't have to mount the sensor, and the computer will always think the cat is good.-Brent Bogrees '89 YJ 4.0L w/ 33" BFG MT's '94 XJ 4.0L w/ 31" BFG AT's
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