The IAG Performance V3 Street Series Air / Oil separator (AOS) is an excellent investment to keep your Subaru vehicle running well. The Street Series AOS maintains OEM PCV system functionality, but supplements its capacity. The Street Series AOS design is based on years of extensive testing on standard and competition applications. The Street Series AOS' large, 1-liter, cast aluminum swirl pot canister more effectively separates oil from the PCV system upstream of PCV gasses’ return to the intake system. The Street Series AOS' fully-heated cast aluminum housing, superior venting, and unique, patent pending, baffle design set it apart from the rest. The Street Series AOS is compatible with all fuel types, extends engine life, improves crankcase ventilation and is compatible with standard ECU calibrations.

Keeping oil out of the engine intake tract is extremely important towards preventing premature mechanical failure and maintaining performance. Oil in the intake tract of the engine has several detrimental effects. First, the oil coats the internal portions of the intake, intercooler, and piping. This oil may cause premature failure of rubber or silicone hoses, which leads to failed connections.
Once the oil reaches the intake tract it will directly enter the intake manifold and then the combustion chamber of the engine. Oil inside of the combustion chamber can cause detonation and preignition, high emissions, smoke, loss of power, decreased gas mileage, and even catastrophic engine failure, leading to expensive repair bills.

The IAG AOS is designed to be maintenance free. Unlike traditional catch-can systems, our Air Oil Separators do not not require regular draining and maintenance. Once the system is installed there is no further maintenance required. Separated Oil collects on the walls of the AOS can and slowly drains out the bottom by gravity back into the engine's crankcase. Because of our unique heating system the captured oil does not contain sludge, so there’s no danger to recirculating the oil back into the engine.The large volume of the AOS body allows plenty of time for the oil to drain back without the danger of overflowing like some smaller catch cans.

The IAG Air Oil Separator features a unique baffle system to allow the oil suspended in your engine’s PCV gasses to collect and drain back to the crankcase. The position of each inlet hose on one side of the AOS body helps to create a “swirl” of the gasses inside. As the gasses enter they swirl around the inside of the AOS body and are funneled through a series of baffles. Each of these surfaces helps to collect oil while allowing the gasses to escape from the top of the AOS. Because the OEM PCV operation is maintained, the engine also pulls vacuum on the AOS assembly to further evacuate the PCV gasses.

The Street Series AOS maintains the OEM PCV system functionality, but supplements its capacity. The Street Series AOS PCV discharge gasses return to the turbo inlet, retaining a PCV valve to draw additional suction, improving air oil separation. The Street Series AOS protects from oil dilution and lubrication failures in ethanol fueled application because the Street Series AOS captures fuel vapors out of the oil and returns these vapors to the intake tract for combustion. The Street Series AOS protects from both oil entrainment in the intake flow and oil dilution in the engine's lubrication system far better than the OEM PCV system alone.

The IAG Street Series Air Oil Separator features a unique heating system to solve a common issue with inferior catch cans. By attaching the AOS to the vehicle’s cooling system we are able to transfer the heat from the engine into the AOS. When the hot PCV gasses travel through a cold hose condensation forms inside. Over time this condensation mixes with the oil in the system and causes sludge. By heating the AOS body to the same temperature as the engine, the condensation, and the associated buildup, is reduced or nearly eliminated.

For the 2022+ Subaru WRX our engineers set out to make the system as easy to install as possible. We’ve developed specially designed custom injection molded fittings to connect to the unique breather ports of the 2022+ Subaru WRX. These fittings are plug-and-play to the OEM breather ports, so no modifications are required to the fittings. The AOS is offered in your choice of three colors to accent your engine bay.