I have a 93 dx hatch that someone swapped a GSR into, I believe this car had the firewall mounted map sensor and the swap has one on the throttle body, they used the harness for the gsr I believe. the car keeps pulling code 3 for the map sensor and I tested voltage to the pigtail it would test around 2v, I don't see the cabin harness map plug only the one on te harness, I'm stumped and don't know where to go next I've tried 3 different map sensors. Any and all help is appreciated!

 

The firewall based map sensor plug comes from the battery side engine bay harness. You might find the plug somewhere around your battery. If you can't even find cut wires (fresh electrical tape?) in that vicinity then I would suspect it didn't have the firewall map originally.

I'll go down to my wife's car and take a pic and edit my post so you can exactly where it comes out of the harness.



I am pulling on the map sensor which now is hooked to the throttle body map (was a firewall but has had a motor swap). I found the engine harness map plug and looked it all up in my ETS manual to discern what each plug was etc. I have two map sensor plugs, but the original is the one being used.



It is secured the firewall and runs down beind the battery, it's the dirty one in the picture.



It come out from under the battery and runs into the main harness here in front of the battery.