Cobb Tuning Subaru Air/Oil Separator FXT 2009-2013, LGT/OBXT 2005-2009, WRX 2008-2014, STI 2008-2021 - 822615EMISSIONS 50 State Legal. This part is legal for sale and use on Emissions Controlled Vehicles in all 50 states when used in accordance with the manufacturer's application guide because it has a California Air Resources Board (CARB) Executive Order (EO) number: D 660 25 D 660 45 DESCRIPTION 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.