AEM Induction 21-478C Cold Air Intake System for 2008-2014 Subaru WRX and STI

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. Associated products: AEM-1-1000 Air Filter Cleaner

• Utilizes washable, reusable, oil-free synthetic filter media that preserves airflow efficiency, traps harmful contaminants, and provides long-term value over disposable filters.

Upgrade the intake performance of your compatible Subaru WRX or STI with the AEM Induction 21-478C Cold Air Intake System. Designed to increase horsepower and torque, this system replaces restrictive factory intake components with a mandrel-bent aluminum intake tube, a custom heat shield, and an oversized AEM DRYFLOW synthetic air filter. The gunmetal gray finish provides a clean, performance-oriented appearance while supporting reliable operation in demanding driving conditions.

The reusable, washable, oil-free synthetic filter is engineered to provide strong airflow while trapping harmful contaminants without filter oil. Under normal highway driving conditions, the oversized conical filter can typically be serviced at intervals of up to 100,000 miles. The custom heat shield helps isolate the filter from high engine-bay temperatures, and the factory fresh-air duct attaches directly to the shield to help maintain a consistent supply of cooler intake air.

Installation can typically be completed in less than 90 minutes using quality included hardware and standard hand tools. The mandrel-bent aluminum construction supports smooth airflow and long-term durability, while the AEM Lifetime Limited Warranty provides additional product assurance. This intake system is intended for the listed Subaru applications and is not CARB approved; verify emissions requirements before installation. AEM-1-1000 Air Filter Cleaner is available separately for maintaining the reusable filter.

Key Product Specifications and Technical Data

• Brand: AEM Induction
• Part Number: 21-478C
• Product Type: Cold air intake system
• Finish: Gunmetal gray
• Filter Type: Oversized conical DRYFLOW synthetic filter
• Filter Media: Washable, reusable, oil-free synthetic media
• Intake Tube Material: Mandrel-bent aluminum
• Warranty: AEM Lifetime Limited Warranty

What's Included

• Mandrel-bent aluminum intake tube
• AEM DRYFLOW synthetic air filter
• Custom heat shield
• Installation hardware

Fitment

Fits select 2008-2014 Subaru Impreza, WRX, and STI applications. Confirm the exact vehicle configuration and model year before ordering. This product is not CARB approved, and applicable emissions regulations should be reviewed before installation.

Features:

• Performance Improvement: Designed to increase horsepower and torque by improving intake airflow.
• DRYFLOW Filter: Includes a washable, reusable, oil-free synthetic filter that supports airflow efficiency and contaminant control.
• Extended Service Interval: The oversized conical filter can typically go up to 100,000 miles between services under normal highway driving conditions.
• Heat Protection: Custom heat shield helps protect incoming air from high engine-bay temperatures while connecting to the factory fresh-air duct.

Fitments:
2008 Subaru Impreza WRX
2008 Subaru Impreza WRX STI
2009 Subaru Impreza WRX
2009 Subaru Impreza WRX Premium
2009 Subaru Impreza WRX STI
2010 Subaru Impreza WRX
2010 Subaru Impreza WRX Limited
2010 Subaru Impreza WRX Premium
2010 Subaru Impreza WRX STI
2010 Subaru Impreza WRX STI Special Edition
2011 Subaru Impreza WRX
2011 Subaru Impreza WRX Limited
2011 Subaru Impreza WRX Premium
2011 Subaru Impreza WRX STI
2011 Subaru Impreza WRX STI Limited
2012 Subaru Impreza WRX
2012 Subaru Impreza WRX Limited
2012 Subaru Impreza WRX Premium
2012 Subaru Impreza WRX STI
2012 Subaru Impreza WRX STI Limited
2013 Subaru Impreza WRX
2013 Subaru Impreza WRX Limited
2013 Subaru Impreza WRX Premium
2013 Subaru Impreza WRX STI
2013 Subaru Impreza WRX STI Limited
2014 Subaru Impreza WRX
2014 Subaru Impreza WRX Limited
2014 Subaru Impreza WRX Premium
2014 Subaru Impreza WRX STI
2014 Subaru Impreza WRX STI Limited

Air Freight Prohibited: false
Not Carb Approved: true
Carb Acknowledgement Required: true
Ltl Freight Required: false
Prop 65: Y
Part Type: automotive
Epa: N/A
Regular Stock: t
Units Per Sku: 1