Update:
Verified that one side of each Heated O2 circuit in connected to the fuel pump relay and the other side of each is connected to the pin 12 and 66 respectively of the ECU. Based on the behavior of the Heated O2 circuit I figured it would be a good idea to check Battery and gnds per the table on 24a-13. And wow, no battery voltage between 10 and 54 and also 33 and 54. I’m assuming that pins 10 and 33 (ECU) are tied together through the Throttle valve motor switch. Verified continuity between ECU pin 10 and the ITA Sensor brown/blue wire. Next step in the morning will be to verify everything so far then identify physically where the gnd connection is for the injector wiring harness…….I hope the hell it’s not under the intake manifold. If somebody has any ideas, feel free.




