[j.fro]

I've had MAF issues that could be 124/125.01/ECU related. My car was running with the 125.01 after the change and "update" (shop didn't get it right). During a Dyno test I discovered it was running lean. Chased the lean condition for years, and when I went back to a 124 the lean condition was resolved and the car ran much better.
Use your Durametric to check your pre-cat O2 sensor voltages. They should average 0.45, going up and down a bit. If they sit at 0.1 or less, you're lean.