Electrical Code 22 - New BAP and resistances all good

I have been troubleshooting a Code 22. I have an 87 but the car has an 89 Harness and A9L ECM, full MAF conversion.

-I checked the test harness ground and its good.
-I checked the resistance between the MAP/BAP connector, TPS connector, and EGR connectors (ground wires) and all checks good.
-Resistance from the BAP/MAP sensor plug to ground (neg battery terminal) is good.
-The BAP/MAP connector shows 5V with the ignition on, orange wire.
-All pointed to a bad sensor. My DVM doesn't read HZ so I took the chance.

-I swapped the MAP sensor for a new NAPA BAP sensor and no change to the codes.
-I had a bad experience with a bad/new EGR sensor and so I bought a second new BAP sensor "Standard" brand from O'reillys and no change to the codes.

-The A9L ECM was recently refurbished due to a couple burned pins caused by a burnt O2 sensor wire.

I am at a loss on what to check next. Maybe the ECM isn't getting the signal, a break in the wire somewhere?

Thanks,
Jason

Good advice. I do need to make sure all the codes are being erased. I am also going to check connectivity all the way to the ECM.

Thanks,
Jason

Here is the latest.

I have re-verified the resistances. Interesting side note, the resistances are all in spec with the ignition off but the doors need to be shut and underwood light disconnected. Otherwise those lights mess up the resistance readings....usually around 7.5 ohms. Otherwise, with the negative battery terminal disconnected all resistances are down around .3 ohms to the terminal connector.

I have also used my DVM to verify connective down to the ECM connector. Pin 45, 46, 25 and other associated pins are all good. I cleaned all the related grounds including the main negative batter terminal ground. The car runs smoother but I am still getting code 22. Additionally, I verified the ECM internal ground between pins 40 and 60 is within spec.

I also ran an additional ground from the test connector. That lowered the resistance a little more but it was already in spec. I wanted to rule out a bad ground as the problem as everything else checked good.

I am leaning towards both the Standard BAP and the NAPA Bap both putting out bad signals. I can't verify this but what else could it be. I think I may need to purchase a Ford Motorcraft BAP. Otherwise I think I have ruled out any other possibility.

Thoughts?

Thanks,
Jason

I do not have the vacuum line hooked up.

I also recently purchased a new Motorcraft BAP/MAP. Still getting code 22. I am letting the car sit with the negative battery terminal disconnected just in case its not properly dumping the codes through the reader.

I re-verified, for the third time, that all resistances are good. I am beginning to think it could be a connector problem... maybe a bad connection inside the connector. I have a spare I can try but I dont want to hack my harness if I can avoid it.

Jason