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Enhance your 2019-2021 Subaru WRX STI with the AEM Induction Cold Air Intake System, Part 21-863C, designed to boost horsepower and torque for improved performance. This system features an oversized AEM DRYFLOW synthetic washable air filter, engineered to deliver superior airflow and filtration capabilities. The conical filter design allows for up to 100,000 miles of service under normal highway driving conditions, reducing maintenance and ensuring consistent performance. Paired with a mandrel-bent aluminum intake tube and high-quality hardware, this intake system optimizes airflow efficiency while maintaining durability. A custom heat shield protects the intake air from the high temperatures of the engine bay, ensuring cooler, denser air enters the engine for maximum power gains. The factory-style air duct attaches seamlessly to the heat shield for an easy installation process that can typically be completed in less than 90 minutes. This cold air intake system is guaranteed to increase horsepower and torque, providing noticeable improvements in acceleration and overall engine responsiveness. Backed by AEM*s Lifetime Limited Warranty, this intake system offers both performance and peace of mind for your Subaru WRX STI. Designed specifically for the mentioned model years, it ensures perfect fitment and optimal performance enhancements.
Features:
Fitment:
Subaru WRX STI Base 2019
Subaru WRX STI Base 2020
Subaru WRX STI Base 2021
Subaru WRX STI Limited 2019
Subaru WRX STI Limited 2020
Subaru WRX STI Limited 2021
Subaru WRX STI S209 2019
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.
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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).
