AEM Induction 21-856C Performance Cold Air Intake for 2017-2019 Subaru Legacy 2.5L H4

The AEM 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 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 air intake tube is constructed from mandrel-bent aluminum featuring a durable gunmetal gray powder coated finish. This air intake system was developed to accommodate the engine's factory emissions control devices including the mass airflow sensor and breather tube. The tapered 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 vehicle applications to determine the legal status for each vehicle. AEM's Performance Cold Air Intake Systems are designed, tuned and dyno-tested to give your engine more power and acceleration by replacing the restrictive factory air filter, air intake tubing and air box assembly. Associated products: AEM-1-4007 Air Filter Wrap, AEM-21-2027DK AEM DryFlow Air Filter, 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.
• AEM Lifetime Limited Warranty

The AEM Induction 21-856C Performance Cold Air Intake System is engineered for select 2017-2019 Subaru Legacy models equipped with the 2.5L H4 engine. Replacing the restrictive factory air filter, intake tubing, and airbox assembly, this system is designed to improve airflow, throttle response, horsepower, torque, and acceleration. Each application is specifically designed, tuned, and dyno-tested for reliable performance while retaining compatibility with the vehicle’s factory emissions control components, including the mass airflow sensor and breather tube.

Air enters through an oversized AEM Dryflow synthetic air filter positioned in the original airbox area. The oil-free, washable, and reusable filter media provides effective contaminant filtration while maintaining airflow efficiency. Depending on driving conditions, the filter can be used for up to 100,000 miles before cleaning is required. A protective heat shield helps reduce exposure to engine-bay heat, while the mandrel-bent aluminum intake tube features a durable gunmetal gray powder-coated finish for long-term service.

The AEM Induction 21-856C is designed for straightforward installation using commonly available tools and is backed by AEM’s Lifetime Limited Warranty. Associated service products include the AEM 1-4007 Air Filter Wrap, AEM 21-2027DK DryFlow Air Filter, and AEM 1-1000 Air Filter Cleaner. This intake is not approved for sale or use in California or other states that adopt California emissions standards; verify emissions legality for the specific vehicle application before purchase. California emissions acknowledgement may be required. Proposition 65 warning applies.

Key Product Specifications and Technical Data

• Brand: AEM Induction
• Part Number: 21-856C
• Product Type: Performance cold air intake system
• Application: Select 2017-2019 Subaru Legacy models
• Engine Compatibility: 2.5L H4 gasoline engine
• Intake Tube Material: Mandrel-bent aluminum
• Filter Type: Washable, reusable, oil-free synthetic AEM Dryflow filter
• Warranty: AEM Lifetime Limited Warranty

What's Included

• Aluminum intake tube
• AEM Dryflow synthetic air filter
• Heat shield
• Required intake system components and installation hardware

Fitment: 2017-2019 Subaru Legacy applications equipped with the 2.5L H4 engine. Confirm exact vehicle configuration and emissions requirements before installation.

Features:

• Performance airflow: Replaces restrictive factory intake components to support improved horsepower, torque, throttle response, and acceleration.
• AEM Dryflow filter: Uses washable, reusable, oil-free synthetic media for efficient filtration and long-term airflow performance.
• Heat protection: Includes a protective heat shield designed to reduce intake air temperature by limiting exposure to engine-bay heat.
• Durable construction: Features a mandrel-bent aluminum intake tube with a gunmetal gray powder-coated finish and includes AEM’s Lifetime Limited Warranty.

Fitments:
2017 Subaru Legacy 2.5i
2017 Subaru Legacy 2.5i Limited
2017 Subaru Legacy 2.5i Premium
2017 Subaru Legacy 2.5i Sport
2018 Subaru Legacy 2.5i
2018 Subaru Legacy 2.5i Limited
2018 Subaru Legacy 2.5i Premium
2018 Subaru Legacy 2.5i Sport
2019 Subaru Legacy 2.5i
2019 Subaru Legacy 2.5i Limited
2019 Subaru Legacy 2.5i Premium
2019 Subaru Legacy 2.5i Sport

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