1990 Toyota pick up SR5 4×4 extended cab 3VZE Calif emission 157,000 miles I have owned the vehicle since new.

Truck was running fine until last week when it started idling rough and the check engine light came on. I tested and got code 71 for EGR Valve. I removed and clean the valve and reinstalled it, which cleared the code and the vehicle was running normally again.

I then change the air filter and went to bed. The next morning I got up and the truck was running very rough and would not idle without stalling. The exhaust is horrible I assume from a ton of unburnt gas. It is now throwing a code 32 which according to the factory manual is an Air Flow Meter issue.

Diagnosis = Open circuit in E2, or short between Vc & Vs also, I noticed that the wiring harness to the airflow meter had gotten trapped between the hood and fender when I closed the hood. I was concerned this may have caused a short or disrupted the wires so I opened up the wiring harness and visually inspected. All looks good. I checked continuity on the three circuits E2, Vc & Vs between the airflow meter to the ECU. All good.

Code 32 Trouble Areas:
1. Air Flow Meter circuit
2. Air Flow Meter
3. ECU

I did a resistance test on the airflow meter terminals as per the factory manual and everything was within specification. Does this mean the Air Flow Meter is good?

I checked as carefully as possible for vacuum leaks or leaks in the air intake system using visual inspection and spraying carb cleaner on the various connections. Found nothing.

Currently, the engine starts right up and idles high initially and then quickly starts to idle rough and then dies. If I remove the connection to the TPS the engine will idle much better and does not die.

Is it possible I killed the Air Flow Meter part of the ECU by slamming the hood on the wiring harness even though there is no visible damage?

New and remanufactured ECU's do not seem to be available any longer. My only option is a used one from a scrapyard.

Is there anything I've missed before spending $140 on an old ECU that may or may not solve my problem?

Thanks for listening.