Perrin Black Cold Air Intake - 16-17 Subaru WRX STI - PSP-INT-323BKIncrease horsepower and style under your hood. The PERRIN Cold Air Intake (CAI) system uses proper MAF alignment and tubing size, which are crucial for maintaining proper air fuel ratios and preventing check engine lights that plague competitors. NOTE: This intake system requires no tuning to operate properly and safely! However, if you choose to add an upgraded downpipe or tune, you must choose a tune that is specific to either the PERRIN or AEM