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The AEM 21-508R 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 Honda Civic SI 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 relocated to the driver-side wheel well which is designed to reduce intake air temperature and increase horsepower. The intake tubing is constructed from mandrel-bent aluminum featuring a durable red powder coated finish. This air intake system was developed to accommodate the engine's factory emissions control devices including the inlet air temperature sensor and a replacement breather hose. 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 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 21-508R vehicle applications to determine the legal status for each vehicle.
Installation Instructions

New Unused Product Returns:

Your complete satisfaction is our priority. If an item purchased from aemelectronics.com does not meet your expectations, it may be eligible for return.

  • You may return new, unused parts within 90 days from the purchase date for a complete refund or exchange. To avoid a restocking fee, you must request a return within 60 days of purchase date, and AEM must receive the returned items within 90 days after purchase date.
  • Parts not eligible for return: Clearance items, Factory Refurbished Items, and Made to Order items.
  • Items returned 91-180 days after the date of purchase will be subject to a 15% restocking fee
  • Items are not eligible for return after 180 days unless there is a valid warranty issue and submission. The product must be in the original, manufacturer's box and must be sent freight prepaid
  • Products that show signs of excessive age, abuse, improper handling, or have been modified beyond AEM’s instructions may be rejected and incur an inspection fee regardless of age
  • Original shipping charges are non-refundable

AEM Performance Electronics Limited Warranty

AEM Performance Electronics (“AEM Electronics”) warrants to the original consumer that all AEM Electronics Products will be free from defects in material and workmanship under normal and proper use for a period of 90 days from the date of the original purchase.

For purposes of illustration, but not limitation, the following are not defects in material or workmanship: (a) normal wear and tear and/or required maintenance; (b) improper handling, storage, installation, lubrication or maintenance; (c) damage resulting from or related to misuse (including use in a way other than those applications recommended by AEM), abuse, unauthorized modification or alteration, incorrect polarity (+&- wires crossed), accident, acts of God, or external causes; and (d) cosmetic damage (nicks, bruising, discoloration).

EXCEPT WHERE PROHIBITED BY LAW, THIS WARRANTY IS EXCLUSIVE AND THE ONLY WARRANTY APPLICABLE TO THE PRODUCT. IT IS OFFERED EXPRESSLY IN LIEU OF ANY OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ALL OF WHICH ARE DISCLAIMED.

Limited Remedies: If a Product fails because of a defect in material and/or workmanship within this limited warranty period, AEM will repair or replace the Product at no cost to the customer. This warranty is limited to the repair or replacement of the AEM Electronics Product. In the event of a defect, to the extent permitted by law, these are the customer's sole and exclusive remedies.

Incidental and Consequential Damage Disclaimer: EXCEPT WHERE PROHIBITED BY LAW, AEM ELECTRONICS DISCLAIMS AND UNDER NO CIRCUMSTANCES SHALL BE LIABLE FOR SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR LOSSES RESULTING FROM THE USE, MISUSE, OR INABILITY TO USE THE PRODUCT AS WELL AS ANY BREACHES OF THIS WARRANTY OR ANY IMPLIED WARRANTY REGARDLESS OF THE CAUSE AND EVEN IF THE CLAIMED DAMAGES OR LOSSES WERE CAUSED BY A WARRANTABLE DEFECT.


This warranty applies only to the original purchaser of the Product and is non-transferable, except as prohibited by applicable law.


In no event shall this warranty exceed the original purchase price of the AEM Electronics Product.


Warranty returns will only be accepted by AEM Electronics when accompanied by a valid Return Merchandise Authorization (RMA) number and a dated proof of purchase.


Please note that before AEM Electronics can issue an RMA for any Product, it is first necessary for the installer or end-user to contact our technical support team to discuss the problem. Most issues can be resolved over the phone. Under no circumstances should a Product be returned, or an RMA requested before our support team is contacted. This will ensure that if an RMA is needed that our team is able to track your Product through the warranty process.


PRODUCTS OUTSIDE OF WARRANTY PERIOD

Most AEM Electronics Products, excluding discontinued products, can be replaced (at a discounted rate) following documentation of the faulted item being field destroyed. A valid Return Merchandise Authorization (RMA) number must be issued by the Support Team before a transaction for Product replacement can occur.

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AEM

**AEM (Advanced Engine Management)** is a premier brand specializing in high-performance automotive parts and electronics. Known for innovation and quality, AEM offers a wide range of products, including air intake systems, fuel management systems, and engine tuning solutions. Designed to enhance performance and reliability, AEM products are trusted by enthusiasts and racers worldwide for pushing the limits of what's possible on the street or track.

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