The COBB Air/Oil Separator (AOS) for Subaru WRX (2015-2021) helps prevent crankcase oil vapors from entering the intake system, reducing carbon buildup and maintaining fuel octane levels. Developed in partnership with IAG Performance, it features a compact cast aluminum body, 1-liter capacity, integrated ORB ports, and a coolant bleeder valve. The heated AOS design maximizes water evaporation to prevent mixing with oil, while the snail-shaped base enhances oil drainage.

• Features:

  • Compact cast aluminum tank with wrinkle black powder coat

  • 1-liter holding capacity

  • Integrated ORB ports and coolant bleeder valve

  • Laser-etched COBB logo

  • Bespoke COBB anodizing on caps

• Emissions:

  • 50 State Legal (CARB EO: D-660-25, D-660-45)

• What’s in the Box: AOS unit, mounting hardware, hoses, installation instructions

• Warranty: Manufacturers warranty

Fitment:

• WRX 2015-2021