CEL guru's please help!!!

[93NOTCH]

Hey guys, I recently swaped a obd2 LS into my 5th gen DX. I got the obd1 computer but am using the obd2 harness, dizzy and injectors. Everything is running good and smooth with the exception of one thing. Once I start the car its idles normal for a couple seconds then a check engine light pops on and the idle jumps up about to about 1300 rmp and holds. The car is also running super rich and mpg sucks......now I pulled the code and it registered the MAP sensor being the culprit.....I also changed the O2 sensor just to be sure but nothing changed......Im hesitant to think is the MAP because those syptoms dont seem characteristic also the motor only has 48K on it. Also should note the previous owner had an ITR motor in it. Any suggestions would be very appreciated!!!!

 

[George777]

Did you try using the right ECU? From what I read, you are using everything else OBD2 but an OBD1 ECU? I would start there.

 

[93NOTCH]

The ECU is a P75 for manual transmission, and again its OBD1, Ive heard of many people running the same combo with no problems.....Dasfinc for example.

 

[crvtt96]

A map sensor senses engine load so if it is bad or sees low vacuum (telling ECU to richen mixture) a map or vacuum problem could cause your problem. Also is that ecu chipped or tuned?

 

[93NOTCH]

Yep it turned out the guy who had the shell before me with the ITR in it had to extend the MAP sensor plug. He did it from the firewall side of the harness and bypassed the shock tower plugs alltogether and ran it directly to the MAP sensor. Unfortunately he tucked the plug away and I didnt see it. I was using the plug from the engine harness I got with the motor. Obviously the computer was not reading the sensor hence the code and rich condition. I plugged in the extension he made and all is good, no more CEL. Thanks for all the replies!