I have two mass air sensors for my car, one I got about 6 months ago and the original stocker. My question is with the original MAF in the car my BL's at idle are 131 but when I put in the newer MAF my BL's are around 121 to 123. What makes the two sensors read differently?? Is it that the original is bad or the new one. My AF reading on the SM is 05 for the old and 06 for the new. Just another one of my "dumb question".