Overtake Post MAF Hose KitSmoother airflow where it matters most The factory post MAF hose on 20022007 Subaru WRX and STI models uses a corrugated rubber design that disrupts airflow immediately after it passes the MAF sensor. Those accordion style folds create turbulence and dead zones, reducing airflow quality, throttle response, and boost consistency right before the turbo inlet. The OVERTAKE Post MAF Hose Kit replaces that compromised OEM design with a smooth bore, 5 ply