Hey guys....I posted a while ago about a loss of power situation on my fathers 90 740GL. to make a long story short he replaced the fuel pump and the fuel pressure regulator. The car ran absolutely beautiful for about 3 weeks. Then yesterday the car started to feel like it was running out of gas and the check engine lite came on. i checked the DTC and the code was 2-2-1 which is fuel trim too lean at part load. Now...my question is....is this code very common when your AMM is no good anymore. I checked the connector w/ my voltmeter and I recieved 1 ohm on the ground side....which I believe to be OK. However on the signal wire...I got 2.9v at idle. The FAQ says it should be 2.3v at idle. Also my fathers car was not warmed up so I don't know for sure if that will matter. What is common w/ code 2-2-1?? Am I in the right direction w/ the AMM??

And...does anyone have a good link where i can get an AMM if needed for the cheapest possible price.