Well, without seeing it, id say you probably have the maf tube the wrong diameter. You are talking about making your own cai, right? If you made your own cai, you have to keep the diameter of the tube, at the maf sensor, the same diameter. If you dont, the calibration with be off, even 2mm can screw it up. The only way to correct that is with a tuner or change the diameter of the tube back to the stock size.