keep the k&n and stock air box the design and shape of the box controls equal velocity through the MAF sensor, CAI's channel air along one side of the tube do to the elbow coming out of the fenderwell, fluctuating the air past the sensor giving a false reading to the computer.Buy a 76mm C&L mass air with inlet tube and be done with the (ribs) a 19lb calibration tube and you can interchange cal.tubes with later performance upgrades.