Experience the power of the K&N drop-in air filter with an innovative, layered design that boosts airflow and horsepower. Engineered for quick, drop-in installation in factory air boxes, it functions as a K&N 05 WRX air filter, a 99-06 Impreza air filter, or a 99-04 Legacy air filter—delivering superior engine efficiency right from the start.

Key Benefits

• Improved airflow for optimal engine performance and increased horsepower
• Washable and reusable design that provides long-term cost savings and durability
• Backed by a 10-Year/Million Mile Limited Warranty for peace of mind
• Designed to reduce MAF sensor contamination with proper cleaning
• Easy installation that saves time and reduces stress during upgrades

Compatibility & Details

Compatible with select Subaru models including the 2003 WRX, 1999–2006 Impreza, and 1999–2004 Legacy variants, as well as specific Forester editions. For a complete overview, please view the Technical Bulletin.

Upgrade your performance today and experience the enhanced benefits of the genuine K&N drop-in air filter. Explore similar quality in our Air Filters – Drop In collection.