domi's general whine-and-whimper thread

[domi]

I had been lead to believe that a car either has MAP or AFM sensors and that the Blacktop had a MAP sensor... Could be wrong there. I am struggling to find a vacuum line diagram for my motor, so i can check if a vacuum leak is at hand. Only insight i have on the issue is that i have between 6 and 12 psi of vacuum on the Fuel Pressure regulator, which is perfect by the book, but i have no clue if it speaks on behalf of the whole vacuum system. The ECU is still registering error code 21, which i believe is short/open O2 sensor heater circuit. Per current research the oxygen sensor terminal going to the ECU has 4 terminals, 1 and 2 being the heater, 3 the sensor signal wire and 4 ground. Weird stuff there:
I tried identifying if everything is wired properly and the 3rd terminal checked out okay - it is the signal wire. Terminal four, which should be ground is the only one that registered resistance between it and the car's body, which i guess is okay, but the weird thing is that when ignition is on and i check for voltage [multimeter negative on battery minus] the supposed Ground terminal has 12V! Terminal 1 is dead and terminal 2, which should have 12V has about 2-3. I'm confused. I mean, even with that as it is if i just route the signal wire and leave the rest open, once the car is warmed up it should have no issues, but it's still bogging. I'm fairly fed up with this now. Problem is if i drive it over to a service shop there's a good chance they wouldn't fix jack, due to the engine not being officially serviced in the US, most they can do is get me in trouble for driving around in an illegaly swapped car. =(