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2003 Subaru Impreza II WRX STI 2.0L H4 Gas Air Intake

- Guaranteed to increase horsepower
- Designed to improve throttle response and engine sound
- Replaces entire factory air intake system
- Not legal for highway use in states adopting California emission regulations
- Washable and reusable lifetime air filter
- Lasts up to 100,000 miles before service is required (depending on driving conditions)
- Easy to install, usually in 90 minutes or less
- K&N No-Hassle Lifetime Limited Warranty
Replacement Filter | RU-70031 |
Air Filter Color | Red |
Air Filter Material | Cotton Gauze |
Air Filter Outlet Shape | Round |
Clamps Included | 1 |
Clamp Material | Stainless Steel |
Clamp Style | Regular |
Couplers Included | None |
Type | Gen I |
Product Style | 57i Series International Kits |
Intake Pipe Color / Finish | Black |
Intake Pipe Material | Aluminum |
Street Legal In All US States | Not legal for sale or use in California on any pollution controlled motor vehicle. |
TUV Approved (Europe) | No |
Weight | 2.9 lb (1.3 kg) |
Product Box Height | 9.13 in (232 mm) |
Product Box Length | 9.13 in (232 mm) |
Product Box Width | 9.13 in (232 mm) |
California Restricted | Not legal for sale or use in California |
Warranty | No-Hassle Lifetime Limited |
Easy Moderate Advanced
Wrench, Extension, Flat Blade Screwdriver, Allen Wrench
60-90 Minutes

- Guaranteed to increase horsepower and torque.
- Mandrel-bent aluminum intake tube paired with oversized oiled cotton air filter.
- Engineered to provide high airflow and exceptional filtration.
- Replaces factory air filter and intake tube.
- Filter only requires cleaning every 100,000 miles under normal highway driving conditions.
- Typical installation can be completed in 60 minutes or less with simple hand tools.
- No-Hassle Lifetime Limited Warranty.
- Will not void vehicle warranty.
Estimated Horsepower Gain | 15.85 HP @ 5050 RPM |
Replacement Filter | RP-5113 |
Air Filter Color | Red |
Air Filter Material | Cotton Gauze |
Air Filter Outlet Shape | Round |
Clamps Included | 3 |
Clamp Material | Stainless Steel |
Clamp Style | Regular |
Couplers Included | 1 |
System Type | Cold-Air Intake System |
Estimated Torque Gain | 12.2 lbft |
Product Style | 69 Series Typhoon Kits |
Intake Pipe Color / Finish | Silver |
Intake Pipe Material | Aluminum |
CARB EO Number | D-269-37 |
Street Legal In All US States | Not legal for sale or use in California on any pollution controlled motor vehicle. NOTE: Some specific models and years may be legal in CA. Check the CARB status on your parts at knfilters.com. |
TUV Approved (Europe) | No |
Weight | 9 lb (4.1 kg) |
Product Box Height | 12.25 in (311 mm) |
Product Box Length | 20.25 in (514 mm) |
Product Box Width | 12.25 in (311 mm) |
Mounting Hardware Included | Yes |
Warranty | No-Hassle Lifetime Limited |
Easy Moderate Advanced
Wrench, Extension, Flat Blade Screwdriver, Allen Wrench
60-90 Minutes
Installation PDF
Installation Instruction Sheet Horsepower Guarantee Dyno Chart - 2004 Subaru WRX 2.0L - 15.85HP Increase
- Guaranteed to increase horsepower and torque.
- Mandrel-bent aluminum intake tube paired with oversized oiled cotton air filter.
- Engineered to provide high airflow and exceptional filtration.
- Replaces factory air filter and intake tube.
- Filter only requires cleaning every 100,000 miles under normal highway driving conditions.
- Typical installation can be completed in 60 minutes or less with simple hand tools.
- No-Hassle Lifetime Limited Warranty.
- Will not void vehicle warranty.
Estimated Horsepower Gain | 15.85 HP @ 5050 RPM |
Replacement Filter | RP-5113 |
Air Filter Color | Red |
Air Filter Material | Cotton Gauze |
Air Filter Outlet Shape | Round |
Clamps Included | 3 |
Clamp Material | Stainless Steel |
Clamp Style | Regular |
Couplers Included | 1 |
System Type | Cold-Air Intake System |
Estimated Torque Gain | 12.2 lbft |
Product Style | 69 Series Typhoon Kits |
Intake Pipe Color / Finish | Wrinkle Red |
Intake Pipe Material | Aluminum |
CARB EO Number | D-269-37 |
Street Legal In All US States | Not legal for sale or use in California on any pollution controlled motor vehicle. NOTE: Some specific models and years may be legal in CA. Check the CARB status on your parts at knfilters.com. |
TUV Approved (Europe) | No |
Weight | 9 lb (4.1 kg) |
Product Box Height | 12.25 in (311 mm) |
Product Box Length | 20.25 in (514 mm) |
Product Box Width | 12.25 in (311 mm) |
Mounting Hardware Included | Yes |
Warranty | No-Hassle Lifetime Limited |
Easy Moderate Advanced
Wrench, Extension, Flat Blade Screwdriver, Allen Wrench
60-90 Minutes
Installation PDF
Installation Instruction Sheet Horsepower Guarantee Dyno Chart - 2004 Subaru WRX 2.0L - 15.85HP Increase