Riddle me this?

Ok so a while back I posted I had a problem with a series of codes. I eliminated 2 of the 4 and am working on the other 2. In this battle we found out the car (91 ST185) has the original engine harness, st205 engine, and a ecu with the "93 MR2" written on it. There is no other writing on the computer. The car has been driven like this for years!!! How is that even possible? Should I get a st205 ecu?

My current problem is trying to locate a ST205 IAT sensor plug because the 91 harness doesn't have the right plug. Can I put a ST185 IAT Sensor in a ST205? Help me get this wrongfully treated ST185 back on the road.

the 91 harness doesnt have that plug. the 91 harness plugs into the afm in which the iat is built into the afm. the st205 engine has 2 iat sensors. one in the intake track and one on the intake manifold. wen the conversion was done, most of the time, they use the existing harness for the afm to splice in iat. i hope that helps!