H4 Cold Air Intake System

The AEM H4 Cold Air Intake System is engineered to deliver increased horsepower and torque for 2019-2021 Subaru WRX STI models with the 2.5L engine. This high-performance replacement for your factory intake system has been designed, tuned, and dyno-tested to enhance engine breathing and improve throttle response. The system utilizes an oversized AEM DRYFLOW synthetic washable air filter, which provides exceptional airflow and filtration while requiring service only every 100,000 miles under typical highway driving conditions. The intake tube is constructed from mandrel-bent aluminum for smooth airflow and is powder-coated for enhanced engine bay aesthetics and corrosion resistance. A custom heat shield is included to prevent hot engine bay air from entering the intake, ensuring cooler, denser air for improved performance. Installation of the AEM H4 Cold Air Intake System is designed to be straightforward, typically completed in 90 minutes or less with basic hand tools. The system is a direct replacement for the factory restrictive intake components. AEM Induction recommends a tune to accompany this intake for optimal performance. This product is not CARB legal and cannot be sold or used in California.