"The biggest difference between the intakes was the quality of the MAF signal. The Injen intake's unorthodox MAF housing design resulted in the ECU needing to pull 15-16% fuel at WOT in places to achieve the targeted air-fuel ratio. Luckily, the 10thGen Civic operates in closed loop at wide open throttle most of the time, but a 16% fuel adjustment is enough to make the car run deep into the 9's AFR without the correction. During part throttle operation, -20% short term trims were seen consistently. The PRL Cobra's "Street MAF" on the other hand was within 2-3% throughout the pulls with the stock MAF curve, and within +/-5-6% during partial throttle. The corrections with the PRL Cobra were consistent with the OEM MAF housing, which is a great feat. What does this mean? If you buy an Injen intake, you're going to need recalibration of the MAF scaling for proper operation."
