Got this car that all of a sudden changed its idle. I replaced the AMM with a used out of the boneyard. Before the idle was high so but would be corrected with the AMM unplugged. Showing the car saturday (selling for my niece) and it ran fine including when I showed the AMM assumption. So monday morning first thing I got a 016 AMM out of a 740 and replaced it before starting the car. The car's idle wandered and ran weak. Revving the engine was met with a miss and poor response until I hit the higher RPMs and then it sort of fixed it self.

Today I unplugged the battery for 4 minutes and it seem to cure the problem. I checked the ECU and its the white label one. Not sure what to think. I've got a buyer but I don't want them to have any immediate challenges with the car. Anyone have some past experience with this?

The car threw out a code before I reset on the #2 socket. It had a 1-2-1. Guessing that was from not having the AMM plugged in. But would that confuse the computer?