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Enhance your 2018 Subaru WRX STI's performance with the AEM 21-836WR Cold Air Intake System, designed to deliver noticeable horsepower and torque gains by replacing the factory air intake components. This system features an oversized AEM Dryflow synthetic washable air filter that provides superior airflow and filtration, ensuring your engine breathes efficiently while maintaining optimal cleanliness. The air filter is conveniently positioned within the original air box space and is protected by a heat shield that reduces intake air temperature, which contributes to increased horsepower and improved throttle response. Constructed from mandrel-bent aluminum tubing with a durable textured red powder-coated finish, the intake tubing is engineered for maximum airflow with minimal restrictions, optimizing engine performance and responsiveness. The system is developed to seamlessly integrate with the vehicle's factory emissions control devices, including the mass airflow sensor, ensuring compliance and ease of installation. The tapered, cylinder-shaped Dryflow filter is made from synthetic media that is oil-free and capable of lasting up to 100,000 miles before cleaning, depending on driving conditions. Installation is straightforward with common tools, making this upgrade accessible for most enthusiasts. Backed by AEM's Lifetime Limited Warranty, this intake system is a reliable choice for those seeking increased power and a more aggressive engine sound. It complies with EPA standards and is designed to be compatible with California emission regulations, with specific applications noted for legal use. Improve your vehicle's airflow, horsepower, and overall performance with the AEM 21-836WR Cold Air Intake System, a proven upgrade for the 2018 Subaru WRX STI.
Features:
Fitment:
Subaru WRX STI Base 2018
Subaru WRX STI Limited 2018
Subaru WRX STI Type RA 2018
Order Processing
All orders are processed and shipped within 24 hours of purchase (excluding weekends and holidays).
Orders placed after 3:00 PM EST may ship the following business day.
Shipping Methods
Customers select their preferred shipping method and speed at checkout.
Shipping times are determined by the carrier and cannot be guaranteed by us.
Tracking information will be provided once your order has shipped.
Shipping Coverage
If your package arrives damaged, please notify the delivery driver immediately and contact the shipping carrier to file a claim.
You must report any missing or damaged items within 14 days of delivery.
After this time, we cannot be held responsible for lost or damaged items.
Return Window
You have 30 days from the date of delivery to request a return.
After 30 days, we are unable to accept returns, exchanges, or refund requests.
Eligibility
Items must be returned in their original condition—unused, unwashed, and with all tags and packaging intact.
Certain products may not be eligible for return (e.g., special-order items, customized products, or perishable goods).
Items that have been altered, installed, or modified cannot be returned.
Return Process
Contact our Customer Support team to request a Return Authorization (RMA) before sending items back.
Once your return is approved, you’ll receive instructions on where to send the product.
Customers are responsible for return shipping costs unless the item was defective or incorrect.
Refunds
Refunds are issued to the original payment method once the returned item has been received and inspected.
Please allow 5–10 business days for the refund to appear on your account.
In some cases, a restocking fee may apply (if applicable, this will be disclosed during your return authorization).
