Report Tuners Rejoice! Free Tuning For M4.4! in Performance Modifications Posted November 11, 2018 1 hour ago, Avinitlarge said: I noticed the same a few years ago, ive still been using the 540 maf though. Personally I think it would be impossible to get the exact calibration without the maf being tested with some sort of air flow testing equipment From what everyone, including Aaron, has said, it's because the sensor doesn't sit in the middle. I'm going to try to modify the placement of the sensor by removing material from the mounting point to center it better.