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Air Intake Kit
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Air Intake Kit (AEM Induction) for 2008-2014 Subaru Impreza, WRX, WRX STI NEW

$ 369 .99

Product Notes

Incl. Dryflow Air Filter/Alum. Tubing/Clamps; Estimated 36 HP Gain @ 5300 RPM; Wrinkle Red;CARB E.O. D-670-21 Install time - 1 hr.
Cold Air Induction System
The AEM 21-478WR Performance Cold Air Intake System produces horsepower and torque gains by replacing your vehicle's restrictive factory air filter and air intake housing. This air intake system was designed, tuned and dyno-tested to fit specific Subaru WRX, WRX STI, Impreza WRX and Impreza WRX STI models. Air enters the system through an oversized AEM Dryflow synthetic washable air filter for outstanding air flow, filtration and performance. The air filter is located in the original air box space and is protected by a heat shield which is designed to reduce intake air temperature and increase horsepower. The intake tubing is constructed from mandrel-bent aluminum featuring a durable textured red powder coated finish. This air intake system was developed to accommodate the engine's factory emissions control devices including the mass air flow sensor. The cylinder shaped AEM Dryflow air filter is made from an oil-free, synthetic filter media that can be used for up to 100,000 miles before cleaning is needed (depending on driving conditions). The air intake system is easy to install with commonly available tools and it is backed by AEM's Lifetime Limited Warranty. Some AEM air intakes are not legal for sale or use in California and other states adopting California emission standards while others are 50 state legal. View the 21-478WR vehicle applications to determine the legal status for each vehicle.
Brand: AEM Induction
Condition: New
See All Other Air Intake Kits
LIFE
TIME
Lifetime Warranty Included
This part is backed by our industry-leading lifetime warranty. Shop with total confidence.
100%money-back 120-dayreturns OE-gradequality
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Specifications & Info


Attribute Value
Air Box Included No
Air Filter Element Washable Yes
Air Filter Height 9.125 In. (232mm)
Air Filter Large End Diameter 6.000 In. (152mm)
Air Filter Outlet Length 2.750 In. (70mm)
Air Filter Outlet Shape Round
Air Filter Outlet Width 2.750 In. (70mm)
Clamp Color Natural
Clamp Material Steel
Clamp Quantity 3
Clamp Style Regular
Coupler Color Not Applicable
Couplers Included No
Estimated Horse Power Gain 36 Hp @ 5300 Rpm
Filter Color Red
Filter Material Non-woven Synthetic
Horse Power Increase 36 Hp
Intake Pipe Color Wrinkle Red
Intake Pipe Inlet Length 19.000 In. (483mm)
Intake Pipe Inlet Shape Round
Intake Pipe Inlet Width 2.750 In. (70mm)
Intake Pipe Material Aluminum
Intake Pipe Outlet Length 19.000 In. (483mm)
Intake Pipe Outlet Shape Round
Intake Pipe Outlet Width 2.750 In. (70mm)
Item Weight 7.400 Lbs. (3.3 Kg)
Mass Air Flow Sensor Included Mass Air Flow Sensor Adapter Included When Required
Mounting Hardware Included Yes
Oil Included No Filter Oil Required
Package Material Paperboard
Package Type Box
Product Box Height 12.250 In. (311mm)
Product Box Length 20.250 In. (514mm)
Product Box Width 12.250 In. (311mm)
Prop 65 (C, R Or CR) Cr
Prop 65 Warning Label Https://www.knfilters.com/images/l/prop65.jpg
RPM 5300
Replacement Filter 21-2029dk
Street Legal Yes
System Type Cold Air Induction
TUV Approved (Europe) No
WARNING CA Proposition 65 Yes

Vehicle Fitment Guide

This part fits the following vehicles:

Subaru 3 models (tapclick to expand)(tapclick to hide)
Impreza 2008-2014 (tapclick to expand)(tapclick to hide)
Swipe left/right to see more info
SubmodelSUB-
MODEL		 Body Style Years Engine Attributes
2.0R Sedan 2008 H4 2.0L AWD Automatic
2.5 GT Hatchback 2010 H4 2.5L Turbo AWD Automatic
2.5 GT Sedan 2009 - 2010 H4 2.5L Turbo AWD Automatic
2.5i Hatchback 2008 - 2011 H4 2.5L AWD Automatic & Manual
2.5i Sedan 2008 - 2011 H4 2.5L AWD Automatic & Manual
2.5i Limited Hatchback 2010 H4 2.5L AWD Automatic & Manual
2.5i Limited Sedan 2010 H4 2.5L AWD Automatic & Manual
2.5i Premium Hatchback 2010 - 2011 H4 2.5L AWD Automatic & Manual
2.5i Premium Sedan 2010 - 2011 H4 2.5L AWD Automatic & Manual
Base Hatchback 2012 - 2014 H4 2.0L AWD Automatic CVT & Manual
Base Sedan 2012 - 2014 H4 2.0L AWD Automatic CVT & Manual
I Limited Hatchback 2014 H4 2.0L AWD Automatic CVT
I Limited Sedan 2014 H4 2.0L AWD Automatic CVT
I Sport Hatchback 2014 H4 2.0L AWD Automatic CVT
I Sport Sedan 2013 - 2014 H4 2.0L AWD Automatic CVT
Limited Hatchback 2012 - 2014 H4 2.0L AWD Automatic CVT
Limited Sedan 2012 - 2014 H4 2.0L AWD Automatic CVT
Outback Sport Hatchback 2008 - 2011 H4 2.5L AWD Automatic & Manual
Premium Hatchback 2012 - 2014 H4 2.0L AWD Automatic CVT & Manual
Premium Sedan 2012 - 2014 H4 2.0L AWD Automatic CVT & Manual
R Hatchback 2011 - 2012 H4 2.0L AWD Automatic CVT
R Hatchback 2009 - 2011 H4 2.0L AWD Automatic & Manual
R Sedan 2011 H4 2.0L AWD Automatic CVT
R Sedan 2009 - 2011 H4 2.0L AWD Automatic & Manual
Sport Hatchback 2012 - 2014 H4 2.0L AWD Automatic CVT
Sport Hatchback 2008 - 2011 H4 2.5L AWD Automatic
Sport Hatchback 2008 - 2009 H4 2.5L AWD Manual
Sport Sedan 2008 - 2009 H4 2.5L AWD Automatic & Manual
Sport Limited Hatchback 2012 - 2014 H4 2.0L AWD Automatic CVT
Sport Premium Hatchback 2012 - 2014 H4 2.0L AWD Automatic CVT & Manual
Touring Hatchback 2012 - 2014 H4 2.0L AWD Automatic CVT & Manual
Touring Sedan 2012 H4 2.0L AWD Automatic CVT & Manual
WRX Hatchback 2008 - 2014 H4 2.5L Turbo AWD Manual
WRX Hatchback 2008 - 2010 H4 2.5L Turbo AWD Automatic
WRX Sedan 2008 - 2014 H4 2.5L Turbo AWD Manual
WRX Sedan 2008 - 2010 H4 2.5L Turbo AWD Automatic
WRX GT Sedan 2010 H4 2.5L Turbo AWD Automatic
WRX Limited Hatchback 2010 - 2014 H4 2.5L Turbo AWD Manual
WRX Limited Sedan 2010 - 2014 H4 2.5L Turbo AWD Manual
WRX Premium Hatchback 2009 - 2014 H4 2.5L Turbo AWD Manual
WRX Premium Sedan 2009 - 2014 H4 2.5L Turbo AWD Manual
WRX SE Sedan 2010 H4 2.5L Turbo AWD Manual
WRX STI Hatchback 2008 - 2014 H4 2.5L Turbo AWD Manual
WRX STI Sedan 2011 - 2014 H4 2.5L Turbo AWD Manual
WRX STI Limited Sedan 2011 - 2014 H4 2.5L Turbo AWD Manual
WRX STI Special Edition Hatchback 2010 H4 2.5L Turbo AWD Manual
XV Hatchback 2011 H4 2.0L AWD Automatic CVT
i Hatchback 2014 H4 2.0L AWD Automatic CVT
i Sedan 2013 - 2014 H4 2.0L AWD Automatic CVT
WRX 2013-2014 (tapclick to expand)(tapclick to hide)
Swipe left/right to see more info
SubmodelSUB-
MODEL		 Body Style Years Engine Attributes
Base Hatchback 2013 - 2014 H4 2.5L Turbo AWD Manual
Base Sedan 2013 - 2014 H4 2.5L Turbo AWD Manual
Limited Hatchback 2013 - 2014 H4 2.5L Turbo AWD Manual
Limited Sedan 2013 - 2014 H4 2.5L Turbo AWD Manual
SE Hatchback 2014 H4 2.5L Turbo AWD Manual
SE Sedan 2014 H4 2.5L Turbo AWD Manual
STI Hatchback 2013 - 2014 H4 2.5L Turbo AWD Manual
STI Sedan 2013 - 2014 H4 2.5L Turbo AWD Manual
WRX STI 2013-2014 (tapclick to expand)(tapclick to hide)
Swipe left/right to see more info
SubmodelSUB-
MODEL		 Body Style Years Engine Attributes
Base Hatchback 2013 - 2014 H4 2.5L Turbo AWD Manual
Base Sedan 2013 - 2014 H4 2.5L Turbo AWD Manual
Sport-tech Hatchback 2013 - 2014 H4 2.5L Turbo AWD Manual
Sport-tech Sedan 2013 H4 2.5L Turbo AWD Manual
Tsurugi Edition Sedan 2014 H4 2.5L Turbo AWD Manual
Verify before ordering — please confirm your vehicle's year, make, model and sub-model specifications before placing your order. If anything is unclear, our customer service team is available to help.

Policies

Shipping Information

We offer fast, reliable shipping on all orders:

  • Ships to all countries via US Postal Service Priority Mail.
  • Most orders ship within 1 business day.
  • Delivery time: 1-4 business days after shipment.
  • International shipping available, including APO/FPO addresses.
  • Tracking information provided for all shipments.
  • Additional handling fees may apply for oversized/overweight packages.

Return Policy

We want you to be 100% satisfied with your purchase. That's why we offer:

  • 120-Day Returns - Return any part within 120 days from date of receipt.
  • Must obtain RMA (Return Merchandise Authorization) number before returning.
  • Parts must be in original condition, uninstalled, unaltered, and in original packaging.
  • Important: Electrical parts are not returnable if unsealed.
  • Please inspect parts upon arrival and notify us within 5 days of receiving incorrect or damaged parts.
  • Refunds processed after warehouse receives return and credited to original payment method.

Warranty

This part comes with a limited lifetime warranty. Warranty begins on the original purchase date.

Warranty does NOT cover:

  • Shipping costs or labor expenses.
  • Installation errors.
  • Parts used for racing.
  • Commercial vehicle parts.
The AEM 21-478WR Performance Cold Air Intake System produces horsepower and torque gains by replacing your vehicle's restrictive factory air filter and air intake housing. This air intake system was designed, tuned and dyno-tested to fit specific Subaru WRX, WRX STI, Impreza WRX and Impreza WRX STI models. Air enters the system through an oversized AEM Dryflow synthetic washable air filter for outstanding air flow, filtration and performance. The air filter is located in the original air box space and is protected by a heat shield which is designed to reduce intake air temperature and increase horsepower. The intake tubing is constructed from mandrel-bent aluminum featuring a durable textured red powder coated finish. This air intake system was developed to accommodate the engine's factory emissions control devices including the mass air flow sensor. The cylinder shaped AEM Dryflow air filter is made from an oil-free, synthetic filter media that can be used for up to 100,000 miles before cleaning is needed (depending on driving conditions). The air intake system is easy to install with commonly available tools and it is backed by AEM's Lifetime Limited Warranty. Some AEM air intakes are not legal for sale or use in California and other states adopting California emission standards while others are 50 state legal. View the 21-478WR vehicle applications to determine the legal status for each vehicle.

Fits Years: 2008 2009 2010 2011 2012 2013 2014

Fits Models: Impreza, WRX, WRX STI

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120
Day Return Window

4× the Industry Standard

Most retailers stop at 30 days. We give you a full four months to install, test, and return for a 100% refund — return shipping on us.

NEW
Direct-Fit Replacement

Engineered To OEM Specs

Brand-new aftermarket parts from trusted suppliers — built to original-equipment specifications so they fit and function like the factory unit, at a fraction of the price.

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