IAG AOS - Subaru WRX/STI (Multiple Options)

The IAG Air / Oil Separator (AOS) is a smart move to protect and enhance your Subaru's performance. Developed over years of extensive testing on a range of standard and competitive applications, the IAG AOS offers unparalleled protection for your 2022+ WRX engine. Our exclusive AOS design incorporates a 1-liter cast aluminum swirl pot canister that significantly improves oil separation from the PCV system before returning PCV gasses to the intake. Crafted from a lightweight yet durable aluminum housing, the IAG AOS provides enhanced ventilation and features an innovative baffle design that sets it apart from the competition. This AOS works with all fuel types, prolongs the lifespan of your engine, improves crankcase ventilation and incorporates our innovative baffle design that sets it apart from competitors’ products.

Oil seeping into the engine's intake tract can have detrimental effects. It is vital to prevent oil from entering the engine intake to avoid premature mechanical issues and uphold optimal performance in your Subaru. Oil coated components in the intake, intercooler, and plumbing can cause rubber and silicone hose connections to deteriorate. Once inside the intake tract, the oil can affect the intake manifold and then the engine’s combustion chamber, potentially triggering detonation, pre-ignition, excessive emissions, smoke, power loss, reduced fuel efficiency, and even engine damage or complete engine failure.

Unlike ordinary catch-can systems, the IAG Air / Oil Separator functions without the need for routine draining or maintenance. The oil separated by the AOS gathers along the canister walls, gradually draining into the engine's crankcase. The spacious design of the IAG AOS prevents overflow by facilitating slow drainage, whereas smaller catch cans may struggle to keep pace and often need manual draining. Our exclusive heating system ensures that the collected oil stays clear of sludge, minimizing the risk of reintroducing it into the engine.

The IAG Air / Oil Separator uses a unique baffle system to collect and drain the oil from your engine's PCV gasses back to the crankcase. The AOS body's inlet hoses create an internal gas vortex, which then filters through the baffles, trapping the oil and allowing the gas to escape from the top of the AOS canister. Because the OEM PCV remains functional, the engine is also able to provide additional vacuum, which helps to remove more of the PCV gasses.

The IAG Air / Oil Separator works with the OEM PCV system, boosting its capacity. It helps channel PCV gasses to the turbo inlet by using an upgraded PCV check valve, providing increased suction and air-oil separation. In ethanol-fueled applications, it prevents oil dilution and lubrication issues by capturing fuel vapors from the oil and reintroducing them for combustion. IAG’s AOS prevents oil from entering the intake and oil dilution in the engine's lubrication system, going beyond the capabilities of the OEM PCV system alone.

Crafted with a lightweight yet sturdy aluminum housing, the IAG Air / Oil Separator is even lighter than our previous AOS iterations. Whether you're drag racing or hitting the track in your Subaru, we value the importance of weight savings. This is why we've fine-tuned and lightened this AOS design to enhance your Subaru's overall performance, guaranteeing you get the best results every time you race or hit the track.

The IAG Air / Oil Separator features a proprietary heating system that capably handles issues frequently encountered in lower-quality catch cans. Unlike inferior designs that allow hot PCV gasses to pass through cold passages, leading to condensation mixing with oil and causing sludge, IAG's improved design is linked to the vehicle's cooling system. This enables the transfer of heat from the engine into the AOS canister. By heating the AOS canister to the engine's temperature, condensation and associated buildup are significantly diminished or completely eliminated.

The IAG Air / Oil Separator is equipped with a full set of custom-length SAE Quick Connection lines, making installation easier and reducing the risk of leaks with a more reliable and secure connection than standard hose clamps. Once installed, the IAG AOS system has the appearance of a factory component that seamlessly blends in with your Subaru’s engine.

We’ve designed the IAG Air / Oil Separator to make the system as easy to install as possible for the 2022+ Impreza WRX. The connection hoses at the canister are custom fitted SAE Quick Connection lines that are the exact length to reach the corresponding engine parts. The IAG Air Oil Separator also includes pre-cut and crimped hoses on applicable Subaru models. The IAG AOS is available in your choice of black, red or neon yellow to compliment the engine bay of your Subaru.