IAG Air / Oil Separator (AOS) Fits 2022-24 Subaru WRX

Part Details:

The IAG Air / Oil Separator (AOS) for the 2022–2024 Subaru WRX is designed to reduce oil carryover from the PCV system before crankcase vapors are routed back into the intake. Built from a lightweight, durable aluminum housing and developed through extensive testing, it helps improve crankcase ventilation and supports long-term engine protection for the FA24F platform.

By keeping oil out of the intake tract, intercooler, and charge plumbing, the system helps reduce oil contamination that can contribute to deterioration of rubber/silicone couplers and potential performance and reliability issues over time.

Key Features

• 1-liter cast aluminum swirl pot canister designed to improve oil separation from PCV gasses before returning them to the intake.
• Unique internal baffle system that promotes oil capture and controlled return to the crankcase.
• Works with the OEM PCV system and supplements its capacity using an OEM-style PCV check valve to help increase suction and improve air-oil separation.
• Maintenance-free design that drains separated oil back to the crankcase without routine emptying.
• Proprietary heating strategy tied into the vehicle cooling system to reduce condensation buildup and help prevent sludge formation.
• Custom-length SAE quick connection lines designed to ease installation and reduce leak risk, with an OEM-like finished appearance.
• Compatible with all fuel types and standard ECU calibrations (per manufacturer description).
• Available in multiple canister colors (Black, Red, Neon Yellow).

Features summarized from the manufacturer’s product description and specifications.

How It Works

PCV gasses enter the AOS and are directed to create an internal vortex. The flow then passes through internal baffles that encourage suspended oil to collect on internal surfaces. The separated oil drains back to the crankcase, while the cleaned vapors exit from the top of the canister. Because the OEM PCV system remains functional, engine vacuum can continue to assist in pulling crankcase vapors for improved separation.

Maintenance-Free Operation

Unlike typical catch-can setups that require periodic draining, this AOS is designed to return collected oil to the engine’s crankcase. The canister volume and drainage strategy are intended to reduce the likelihood of overflow compared to smaller catch cans, while the heating approach is meant to reduce condensation-related sludge.

Fitment

• Vehicle: 2022–2024 Subaru WRX
• Engine: FA24F 2.4L

What’s Included

• Air / Oil Separator (AOS) unit
• Hose and fitting kit
• Mounting bracket

Specifications

• Part Number: IAG-ENG-7188
• Material: Cast aluminum housing with nylon top
• Color Options: Black, Red, Neon Yellow

Installation Notes

• Designed for easier install using custom-length SAE quick connection lines and model-specific hose routing.
• The heating strategy is integrated with the vehicle’s cooling system to help bring the canister up to engine temperature and reduce condensation.
• Follow the manufacturer’s installation instructions for proper routing, connections, and check valve orientation.

FAQs

What does an air / oil separator do?

An AOS separates oil from crankcase vapors (PCV gasses) so less oil is carried into the intake tract. The separated oil is returned to the crankcase while the cleaned vapors continue through the ventilation system.

Is this the same as a catch can?

Functionally they target the same problem (oil in PCV vapors), but this system is designed to be maintenance-free by returning collected oil to the crankcase instead of requiring manual draining.

Will it work with ethanol or different fuel types?

The manufacturer describes the system as compatible with all fuel types and notes benefits for ethanol-fueled applications related to oil control and fuel dilution concerns.

Does it require tuning?

The manufacturer states compatibility with standard ECU calibrations when installed properly.

Will this fit other Subaru models or engines?

This specific kit is listed for the 2022–2024 Subaru WRX FA24F 2.4L. For other Subaru platforms (FA20, EJ-series, etc.), use the correct model-specific AOS/catch can setup.

Recommended for Engine Builds

This IAG Air / Oil Separator is recommended for FA24F-based Subaru WRX applications where proper crankcase ventilation and oil vapor control are important for long-term engine reliability. As boost pressure and sustained engine load increase, effective oil separation helps reduce oil contamination in the intake system.

• Engine upgrades and supporting components for turbocharged Subaru platforms
• Oil catch cans and air oil separators designed to manage oil vapor in PCV systems
• When Is It Time to Upgrade Your Clutch?
• FA20 vs FA24: What WRX Owners Should Know

Learn more about IAG Performance engine and reliability solutions