The COBB Air/Oil Separator is placed within your Subarus crankcase ventilation system and helps to prevent oil vapors from being introduced into the intake system. The COBB Air Oil Separator has been developed in partnership with IAG Performance and offers exclusive features.

• Heat Shielding on Crankcase Breather and Oil Return Lines
• Coolant Bleeder Valve
• Bespoke COBB Color Combination
• Laser Etched COBB Logo

The Subaru EJ engine has 3 ports that vent crank pressure: one on each cylinder head and another on the top of the block. Each engine vent port receives its own connection to the AOS. By giving each engine port its own entrance to the AOS we have allowed for more effective and faster excavation of crankcase pressure. Additionally, this reduces overall system pressure. With a 4" OD and 5.75" height, the AOS has an approximate 1 liter of holding capacity. The larger the AOS, the more power you can safely make without having to worry about the AOS overfilling. The bottom of the AOS is shaped like a snail, redirecting positive crank pressure into the same swirl pattern produced by the 3 side ports. Allowing maximum oil drainage while separating oil from the air in all the venting ports. The back plate of the AOS features a unique coolant routing system that heats the entire AOS to the same temperature of the engine. This maximizes the evaporation of any water collecting inside of the can. The hotter the AOS, the less water will collect inside and mix with the oil. Why? The COBB Subaru Air/Oil Separator helps to prevent crankcase oil vapors from recirculating back through your engine's intake system. Oil vapors passing through your engine's intake system lower the effective octane rating of fuel and can contribute to both oil and carbon buildup over time. Features Subaru Air/Oil Separator WRX 2008-2014, STI 2008-2020

• Billet Aluminum Tank Design
• Bespoke COBB Anodizing on Caps
• Wrinkle Black Powder Coated Canister
• Laser Etched COBB Logo
• Developed in Partnership with IAG Performance

Fitment Subaru Legacy

• 2005 Subaru Legacy GT AT USDM
• 2005 Subaru Legacy GT MT USDM
• 2006 Subaru Legacy GT AT USDM
• 2006 Subaru Legacy GT MT USDM
• 2006 Subaru Legacy GT Spec B MT USDM
• 2007 Subaru Legacy GT AT USDM
• 2007 Subaru Legacy GT MT USDM
• 2007 Subaru Legacy GT Spec B MT USDM
• 2008 Subaru Legacy GT AT USDM
• 2008 Subaru Legacy GT MT USDM
• 2008 Subaru Legacy GT Spec B MT USDM
• 2009 Subaru Legacy GT AT USDM
• 2009 Subaru Legacy GT MT USDM
• 2009 Subaru Legacy GT Spec B MT USDM

Impreza

• 2008 Subaru Impreza STi Hatch MT USDM
• 2008 Subaru Impreza WRX Hatch AT USDM
• 2008 Subaru Impreza WRX Hatch MT USDM
• 2008 Subaru Impreza WRX Sedan AT USDM
• 2008 Subaru Impreza WRX Sedan MT USDM
• 2009 Subaru Impreza 2.5 GT Hatch AT USDM
• 2009 Subaru Impreza 2.5 GT Sedan AT USDM
• 2009 Subaru Impreza STi Hatch MT USDM
• 2009 Subaru Impreza WRX Hatch MT USDM
• 2009 Subaru Impreza WRX Sedan MT USDM
• 2010 Subaru Impreza 2.5 GT Hatch AT USDM
• 2010 Subaru Impreza 2.5 GT Sedan AT USDM
• 2010 Subaru Impreza STi Hatch MT USDM
• 2010 Subaru Impreza WRX Hatch MT USDM
• 2010 Subaru Impreza WRX Sedan MT USDM
• 2011 Subaru Impreza STi Hatch MT USDM
• 2011 Subaru Impreza STi Sedan MT USDM
• 2011 Subaru Impreza WRX Hatch MT USDM
• 2011 Subaru Impreza WRX Sedan MT USDM
• 2012 Subaru Impreza STi Hatch MT USDM
• 2012 Subaru Impreza STi Sedan MT USDM
• 2012 Subaru Impreza WRX Hatch MT USDM
• 2012 Subaru Impreza WRX Sedan MT USDM
• 2013 Subaru Impreza STi Hatch MT USDM
• 2013 Subaru Impreza STi Sedan MT USDM
• 2013 Subaru Impreza WRX Hatch MT USDM
• 2013 Subaru Impreza WRX Sedan MT USDM
• 2014 Subaru Impreza STi Hatch MT USDM
• 2014 Subaru Impreza STi Sedan MT USDM
• 2014 Subaru Impreza WRX Hatch MT USDM
• 2014 Subaru Impreza WRX Sedan MT USDM

WRX

• 2015 Subaru WRX STI Sedan MT USDM
• 2016 Subaru WRX STI Sedan MT USDM
• 2017 Subaru WRX STI Sedan MT USDM
• 2018 Subaru WRX STI Sedan MT USDM
• 2018 Subaru WRX STI Type RA Sedan MT USDM
• 2019 Subaru WRX STI Sedan MT USDM
• 2020 Subaru WRX STI Sedan MT USDM