AEM® 20-402S - Air Bypass Valve

AEM Performance Air Intake Systems
AEM® - Air Bypass ValveAEM® - Air Bypass ValveAEM® - Air Bypass Valve Installation InstructionAEM Authorized Dealer
0 (0 reviews)
Availability: In Stock
Usually ships within 24-48 hours
Have a Question? 800.505.3274
Ask a Specialist Live Chat
Lowest Prices
Price match guarantee
Easy Returns
Quick, Simple, Free
In-House Experts
We know our products
Guaranteed Fitment
Always the correct part
20% offMADE IN USA
Originally $67.49
Add To Cart
Product Details

Universal 2.75" Air Bypass Valve (20-402S) by AEM®. AEM's patented air bypass valve is cheap insurance for your engine. Should the air filter become submerged, the air bypass valve automatically takes over, shutting off induction from the filter and instead drawing air through the valve’s external diaphragm.

AEM You Tube Video Channel AEM Warranty About AEM


  • Virtually eliminates the chance of the intake system ingesting water if the air filter becomes submerged
  • Installs along the upper portion of the air intake pipe
  • Includes complete hardware and installation instructions

Whether you cross over water when four-wheeling off-road or you drive in an area where the roads are frequently flooded, you should think about the possibility of the air filter on your cold air intake system becoming submerged in water. If your engine ingests water you could have catastrophic and expensive engine damage! The patented AEM Air Bypass Valve is cheap insurance against such an occurrence. The bypass valve installs on the upper portion of the intake pipe. If the air filter becomes submerged, the valve closes off induction at the filter, rerouting air through its external diaphragm to keep water out and air flowing in. The Air Bypass Valve comes with complete instructions and all necessary mounting hardware.

Brand: AEM       Part Number: 20-402S       UPC: 840879008062
paypal credit AEM Accessories

John Concialdi and Bob Sullivan co founded AEM in 1987 as a tuning performance shop in Compton California. Both men had extensive technical backgrounds in engines and engine airflow, and in a short time AEM became the go-to company for performance modifications. By 1993, when the company relocated to Gardena California, it had become commonplace to see cars wearing the bright yellow AEM logo winning races. AEM tirelessly dyno tested and worked closely with racers and auto manufacturers in an effort to understand intake energy dynamics. This resulted in the sale of their first air intake kit in 1994. AEM can boast a number of firsts and unique products: They’re the first manufacturer to make an intake system with specific tube lengths and diameters to take advantage of pressure waves in the inlet tract; they developed the first dual chamber intake kit; they designed an air bypass valve to prevent hydro-lock should the air filter ingest water; and they created one of the first hybrid intake systems for modified cars. AEM continues to create innovative products to help you get more power from your car.

Vehicle Fitment This part is universal
Year Make Model Fitment Note
ALL ALL ALL This part is universal
Product Reviews (0)
Product Reviews (0)
More Accessories