The map you create references frequency to airflow in g/second. Essentially what you are doing is telling the ecu what the airflow is for a given frequency,using the ben factor.

I do this on every car I do. 1st I change B0120 to 300 to make sure the pcm is only using the maf,you also need to disable stft, ltft and dfco.

Watch the changes under about 6khz as you can find yourself chasing ridiculous numbers around. Also if you log under 1000rpm it will skew the readings big time.

Final check is to enable ltft and log low rpm light throttle as I find it's real easy to end up being to rich in that range.