COBB Air/Oil Separator Subaru WRX 2008-2014, STI 2008-+ / FXT 2009-2013, LGT/OBXT 2005-2009

The COBB Air/Oil Separator is placed within your Subaru's 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.

The COBB Subaru Air/Oil Separator helps to prevent crankcase oil vapors from recirculating back through your engine's intake system.

• 1 Liter Holding Capacity
• Integrated ORB Ports
• Compact Cast Aluminum Body w/ Black Powdercoat Finish
• Heat Shielding on Crankcase Breather and Oil Return Lines
• Coolant Bleeder Valve
• Bespoke COBB Anodizing on Caps
• Wrinkle Black Powder Coated Canister
  
• 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.

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.