AEM Induction · New
AEM 19-21 Subaru WRX STI 2.5L H4 Cold Air Intake System
MPN 21-863C · Store SKU aem21-863C
Supplier stock checked 11/7/2026, 5:45:40 AM UTC. Adding a part does not reserve it.
Request a return within 30 calendar days after delivery. New parts must be unopened and unused.
Shipping & returns ↗This policy does not limit rights required by law.Free standard shipping on eligible parts orders of $100 or more. Oversized and freight items excluded. Fitment, taxes, availability and final totals are confirmed before payment.
Product details
AEM cold air intake systems are designed to increase horsepower and torque. The system includes an oversized AEM DRYFLOW synthetic washable air filter, engineered to provide outstanding airflow, filtration, and performance, and also features a mandrel-bent aluminum intake tube and high quality hardware. The oversized, conical filter design allows you to go up to 100,000 miles between filter services under normal highway driving conditions. A custom heat shield helps protect intake air from the high temperature of your engine bay, and the factory fresh air duct attaches to the heat shield. The entire system can typically be installed in less than 90 minutes. AEM's mandrel-bent aluminum cold air intake systems are guaranteed to provide an increase in horsepower and torque, and are protected by the AEM Lifetime Limited Warranty. Cold Air Intake System
Manufacturer fitment & guides
Check 21-863C against the manufacturer’s application information below.
Part-specific notes
- Not CARB approved. Destination and intended-use restrictions must be checked before sale.
- Emissions acknowledgement required before purchase.
- California Proposition 65: Y
