I flashed out the fault code and got three:
2-3-2 Fuel system compensating for rich/lean at idle
3-2-2 LG-2.4 /air mass meter hot wire burn-off function not working
1-3-1 Engine RPM signal missing

I ran the test for the burn off function, where I back probed the AMM, and I did get a voltage spike 4 seconds after turning off the car. I don't know how high the voltage got, because it is a digital meter, and the voltage isn't on long enough to get other than a registration.

Does anyone have an idea of what to check out?

The car runs fine. Except for a little rumbling in the exhaust, on decel. Like unburnt fuel backfiring in the exhaust system.

Thanks, John P

 

Welcome to the forum.

1-3-1 Turn ignition off. Disconnect fuel system ECU connector and remove the protective sleeve.Connect avoltmeter between harness side of terminal #1 (brown on 240) and earth (ground). Run starter motor. Voltage reading should be 5 - 7 volts. If it is not Check the wiring between the ignition ECU and the fuel system ECU. If the wiring is OK replace the ignition ECU.

2-3-2 Check intake manifold for leaks. Check fuel pressure.

3-2-2 You have checked for voltage but only had a reading after turning off the car. The reading should be there when you are testing and you should be able to read it. Try again, back probing the connector. Connectthe voltmeter leadsbetween terminal #5 (orange on 240) and earth. Reading should be 12 volts. Now connect the voltmeter leads between teminal #1 (brown/black wire) and terminal #5 (orange). Reading should be 12 volts.