So I've searched until my eyes dried out for several days now. I scored a really nice 97 ZJ Laredo for $600 with 136k on the clock, literally from a little old lady. Runs and looks great. I want to swap in an ax15 trans. There are many write ups to get this done. The problem is that here in NY I can't have a check engine light on when it's done, and no I can't just pop the bulb. I find it hard to believe that in this day and age that no one has figured out how to do this and work with or around the computer. Am I just not finding the answer or is there really no solution to this ? I have found ZERO people that have successfully accomplished this. Can anyone shed some light on this for me ? -Vinny on Long Island-

You're pretty much hosed on an OBDII vehicle when it comes to swapping transmissions.

The ONLY possibility I can think of is if you can find a PCM for an ZG (export) you might find one with a manual trans. IDK if they're OBDII compliant though. Most of those were built in Australia or Austria.

I like the ZG idea but it shouldn't have to be that way. A same year (1997) XJ Cherokee computer has to work. The engine is exactly the same. Maybe the ECM connector needs to be re pinned or some of the sensors are a little different in the way they report back to the computer. There is no way I am scrapping this idea because of some software BS. Anybody actually try the XJ computer idea ?

My first thought was the XJ computer as well. I just did a motor and trans swap and am in CA so know your concerns. My advice to you, is get a Factory Service Manual for your 97 ZJ, and an FSM for an XJ. I do have the FSM for a 2000 and can look at the pin outs if needed, but the ignition systems are different. I think you want to stick to 97 or 98 XJ PCMs (don't remember if those years came with a 5spd) But for starters, look at the two service manuals and compare the pinouts on C1, C2, and C3 connectors (these are the 3 that go to the PCM). I am willing to bet they are almost identical. You may need to do some mods, but wouldn't be much.
I actually swapped in a 2001 dodge ram 4x4 5.9 magnum engine and 46re auto transmission into my XJ. Also swapped to the Dodge PCM, but still had to look at all the pinouts and splice in all 43 wires. She runs great, with one CEL for an O2 sensor. I am working that, suspect it is exhaust leaks due to not quite finishing the exhaust, but other than that no issues.

Thanks for the input 5-9longarmxj. Nice job on the swap. According to what I have read so far, people are making it seem like this is impossible and swapping in a complete drivetrain and PCM, like you did, is easier. But it can't be. It's the same motor. I will swap every sensor, the cluster and anything else I have to. I just can't wrap my mind around it being that crazy to do. Starting with the service manuals is a good idea. This has to work. Anybody else swap an ax15 into their ZJ ? What have you tried to kill the CEL? I don't mind blazing a new trail here. Help me out so I don't have to start at the beginning.

A few people have done the swap on pre-OBDII ZJs. The 93 and 94 model years were available with a five speed, it was dropped in 95. I have only seen one ZJ with a factory five speed in my life. It also had manual windows and door locks.

What about having the ecu reprogramed to not read the auto trans?I'm sure there is a way to do it but probably a nightmare to get it done.Or thinking out loud what about a stick from a later tj and use the ecu and maybe the wiring harness?

Don't like the 42RE you have? I know I had big time issues with mine when I first got it 4 years ago with 180k on it. In fact it wouldn't shift up, only manually, and no downshift either when coming to a stop it would stall. Solenoids and multiple fluid changes fixed that then adjusted the bands like 2 or 3 times, now it's pretty darn good. Just saying, is it worth it? A lot of the RE probs can be fixed.

Good question. I like to shift. I also like to be different. Not too many manuals in zj's. I know for a fact that I will blow up the 42re that's in there. Maybe in my old age I have learned this about myself and I'm planning for its death ahead of time. I'm really not sure. You do bring up a good point. The auto is acting up a little. Leaks a little and was 2 quarts low. Fluid smells burnt. Topped it off, but it's lazy. It seems to get confused on light throttle between shifts. It's not slipping. Just bucks a little while it figures out whether to shift up or down. Holds the gear for too long sometimes until the rpm's are way too high. I haven't messed with it much yet. Maybe I should. This manual swap is apparently not as easy as it should be. Might take a while.

I hear you, and to be sure the RE is known for a few issues, but as I say mine has given me alot more service than expected. After fixing the above, I changed my sloppy distributor and was surprised to find that a great deal of the lingering and hunting between gears resolved itself. Am contemplating the aftermarket band replacement that you can do just with the pan down, but, as long as the adjustment screw is sticking reasonably far out of the nut, it tells me there is still some meat on the band. Lucas Transmission Fix will seal it somewhat and restore some line pressure too. lol.