Limp Mode Issue, Need advise

[fixkick]

Hi All, long story short, I had a 90 Tracker for a long time and loved it, but had to sell it due to life's issues. I have since wanted another one of this little beasts.
That brings us up to today, I was able to get a 1992 4dr 16v manual for very cheap.. It was running in limp mode and the CEL on, but the PO had not had it for very long and he had work done on it, but was done messing with it. The person that worked on it had changed the Radiator and put in a new timing belt. I bought it for $500 and brought it home.

I did the code pull, and the only code it is showing is 23, IAT. So I read all I can on this and it seems this is a big reason it is in limp mode. Thinking this would be an easy fix, I went out to look at the senor, and well there is no IAT sensor on the air box.

Here is where I need the help/advise. I know that in 92, the IAT was iffy it if was there or not, but the ECM thinks it should be there. So that makes me wonder if some PO had changed the ECM with an incorrect one and that is why this little truck has been passed on from new owner to new owner.. 

So anyone have any advise on how to get this code to stop? I am ok with adding the sensor, but I need to find the wires to add it and though I see them on the wire schmatic that is out one this site as red/black and Grey/yellow, I am not seeing the red/black wire in the engine bay.

Is this truck able to be corrected?

this simple , no kidding
the 92 had no IAT, not on the air box filter nor the harness there with connector.
so wrong ECU, in car.
the ECU never lies here, 23 means sensor reads 5 full volts, a dead open circuit. as in missing or its 2 wires cut.

EDU 58B30 is no IAC 92/93 these vins. but in calif first use. 58B10.

first off look at hood sticker see words  california  it is , if not , FED it is.
that is first, for any sensors that fail is that. E33 is calif, E03 is USA FED market codes, on all parts sold. by suzuki, here in USA/

all numbers higher are with IAT on the AIR BOX
seen my PDF


https://fixkick.com/ECU/EPC-ECU96-98/all...9-95NA.pdf


the iAT Is here. id 39 and harness 2 pin plug right there if FED car.

the ECU and hood sticker  must match, for year  and CALIF /fED.

I think the story is CALIF ARB mandated it first, then FED EPA later did same.
1992.
ARB is calif. air  research board, or CAL EPA,