Which PCM do I need?

[94Reborn]

I have a Ranger that I just swapped a 1992 4.0 explorer engine into. I used a 1994 ranger 4.0 engine wiring harness, power management harness, and pcm. The truck runs, and actually runs pretty well, but the check engine light was on. I ran codes, and the codes are 15- KAM power interruption/ memory failure. And 71- which was some pcm code but my book says its for cars only.

My guess is that pcm is either bad, or because its from a 94 which should have 2 o2's and sequential injector firing, the computer just knows it doesn't belong. The weird thing is, I don't have a code for the o2 sensor, or any other codes indicating improper running conditions. Which leads me to believe the pcm is actually faulty. The pcm cal code is HAG0.

I think I want to go with a 92 explorer harness because I believe that year was still no egr, and only one o2 sensor, or a 93 explorer pcm if I install the other o2 as well right? And are both the 92 and 93 explorers MAF?

My main question though is can I still use the 94 ranger 4.0 wiring with the older 92-93 computer or will there be wiring issues? I've heard the injector harness is different for the 94 models? I'm getting slightly overwhelmed!

 

[94Reborn]

Ok, so heres an update. I found that my 94 harness and pcm were NOT sequential firing injection. In 94 only the cali rangers were SFI, so mine was batch which means I can retain the wiring harness. I went to the junkyard and found a 91 Ranger STX 4.0 with manual trans and took the pcm from that. It was a MAF, single o2 sensor, no egr truck, so it should be fairly close to matched for my 92 explorer engine. It started up and ran, but threw a check engine light. Luckily it wasn't anther pcm code, but a 66- MAF voltage low code. If I mess with it and plug and unplug it a few times it will work for a few seconds and the light will go off, but then it will come back. I checked the voltages and I think they're right... so I think I need a new MAF. But now what MAF do I need? Should I go with a 91 ranger, 92 explorer, or 94 ranger sensor?