IAG Air / Oil Separator | AOS

• 2008-2014 Subaru WRX
• 2008-2014 Subaru WRX STI
• 2015-2021 Subaru WRX STI

The IAG Performance Air / Oil Separator (AOS) is a valuable investment to protect and maintain peak performance in your Subaru. Developed through years of meticulous testing on standard and competitive applications, the design of the AOS offers unparalleled protection for your engine. This AOS features a 1-liter swirl pot canister made of cast aluminum. This construction significantly enhances the separation of oil from the PCV system before the PCV gasses are directed back to the intake system. The Air Oil Separator features an aluminum housing that has superior ventilation, and it incorporates an exclusive baffle design that sets it apart from the competition. It works with all fuel types, prolongs engine lifespan, optimizes crankcase ventilation, and seamlessly integrates with standard ECU settings, so no tuning is required.

The presence of oil within the engine's intake tract brings about a range of adverse effects, so preventing oil from entering the engine intake is crucial for avoiding premature mechanical issues and maintaining optimal performance. Initially, the oil coats the internal components of the intake, intercooler, and piping, which can potentially harm or prematurely deteriorate rubber or silicone hoses, eventually leading to compromised connections. Once the oil enters the intake tract, it has access to the intake manifold and then the engine’s combustion chamber. Oil inside the chamber has the potential to trigger detonation, pre-ignition, excessive emissions, smoke generation, power loss, reduced fuel efficiency, and in extreme cases, severe engine damage or even complete engine failure.

The IAG AOS is designed for effortless upkeep. Unlike typical catch-can systems, our Air Oil Separators operate without the need for routine draining and maintenance. Separated oil gathers on AOS can walls and slowly drains into the engine's crankcase. With the help of our unique heating system, the collected oil remains free of sludge, ensuring that there is no risk of reintroducing it into the engine. The substantial size of the AOS body allows for a safe and gradual oil drainage process, effectively removing the chance of overflow commonly observed in smaller catch cans.

The IAG Air / Oil Separator features a unique baffle system that captures the oil suspended in your engine's PCV gasses, which are then able to drain back into the crankcase. The AOS body's inlet hoses are set up to create an internal gas vortex, which is then filtered through a series of baffles. The baffles gather the oil while enabling the gasses to exit from the upper part of the AOS canister. As the factory PCV remains active, this allows the engine to generate a vacuum in the AOS assembly to draw out even more of the PVC gasses.

The AOS works with the OEM PCV system, while also providing a boost to its capacity. The AOS directs PCV gasses to the turbo inlet, using an upgraded PCV valve for additional suction and air-oil separation. For applications using ethanol fuel, the AOS provides protection against problems like oil dilution and lubrication issues. This is accomplished by capturing fuel vapors emitted from the oil and then reintroducing them into the intake tract for combustion. The AOS provides exceptional protection against oil entering the intake flow and oil dilution in the engine's lubrication system, exceeding the capabilities of the OEM PCV system alone.

The IAG Air / Oil Separator uses a unique heating system to solve problems found in lesser catch cans. In inferior models, hot PCV gasses pass through a cold pathway, which causes condensation that mixes with the oil and causes sludge. IAG’s upgraded design attaches to the vehicle’s cooling system, allowing heat from the engine to transfer into the AOS canister. By warming the AOS canister to the engine's temperature, condensation and related buildup are greatly reduced or eliminated.

IAG’s Air / Oil Separator includes a full set of custom length SAE Quick Connection lines that not only simplify the installation of the AOS system, but they also reduce the chance of leakage because they offer a more reliable and secure connection than basic hose clamps. Once installed, our AOS system has a clean, factory-look that integrates seamlessly with your Subaru’s engine.

At JDMuscle, we understand that fast and reliable shipping is crucial. With multiple distribution centers across the nation, most in-stock items are shipped within 1-2 business days. On average, you can expect delivery within 1-5 business days for in-stock items. Please note, however, that some products may ship directly from vendors, which could result in additional delays. Products sourced from overseas may also take longer to arrive.

Free Shipping over $199 Policy

• Free shipping is available only for the 48 contiguous states in the U.S.
• Ground shipping applies to regular-sized items only.
• Oversized items such as lips, hoods, and trunks requiring freight shipping are not included in the free shipping program.
• Some manufacturers may impose a shipping surcharge, which will be excluded from the free shipping program.
• The most accurate shipping costs will be displayed at checkout. If you believe the shipping cost is incorrect, please contact us at sales@jdmuscleusa.com for further review.

Carriers

We ship via FedEx, UPS, USPS, and DHL. While we strive to use the most efficient option, we cannot guarantee which carrier will deliver your order. Your items may arrive in multiple packages through different carriers.

Processing Time and Shipping Cut-off

Orders typically take 24 hours to process, with shipping cut-off at 3:00 PM EST. Transit times vary based on location and carrier. Some items, especially those requiring freight shipping, may have extended processing and delivery times. For freight shipping inquiries, contact us at sales@jdmuscleusa.com.

International and Special Shipping Considerations

• International orders are subject to higher shipping fees. If you would like to review your shipping cost, email us at sales@jdmuscleusa.com with your full address and items you plan to purchase.
• In some cases, shipping costs may be incorrectly calculated for international or oversized items. We reserve the right to adjust the shipping fee and will work with you to negotiate a fair cost if needed.
• Customers can challenge and request a review of international shipping fees, and we’ll do our best to find a lower rate where possible.
• Customs Fees & Import Taxes: The shipping charge you pay does not include customs fees or import taxes. These charges vary by country and are the customer’s responsibility. Please check with your local customs office for more details before placing an order.
• Shipping Cost Adjustments: Shipping rates fluctuate, and while we strive to provide the most competitive rates, there may be instances where the shipping cost you paid is significantly lower than the actual cost. In such cases, we reserve the right to request the difference to ensure we cover our basic expenses. We appreciate your understanding and will always aim to keep shipping costs as affordable as possible.

Address Modifications and Fees

• Any modifications to a shipping address after an order is placed may be subject to additional fees.
• For single, small packages, the flat fee is $20. For larger or multiple packages, the fee may be up to $60 or more.

Freight Shipping Guidelines

• Freight shipments require you to be present at the time of delivery.
• The delivery driver may provide a delivery receipt (Bill of Lading). It is crucial to inspect the shipment before signing.
• Carefully check the packaging for any visible damage (dents, punctures, rips) and notate it on the Bill of Lading.
• Open the package and inspect the product itself. If damage is found, document it in detail on the Bill of Lading, take photos, and contact the shipping company to initiate a damage claim.
• Do not refuse the shipment. Contact us at sales@jdmuscleusa.com for guidance.
• If the delivery driver is unable to wait for inspection, note this on the Bill of Lading.

Failure to document damages before signing the Bill of Lading will void any claims for refunds or replacements.

Pre-Installation Inspection Policy

We strongly recommend inspecting all parts or items upon arrival before installation. If you identify any damage, imperfections or missing components, report them immediately to sales@jdmuscleusa.com. Do not install the item. Please note that reports of damage, defects, imperfections or missing components after installation will NOT be honored.

Package Protection

We do our best to ensure your items arrive to you safely but sometimes things happen. If you utilized our Checkout+ feature, rest assured that your package is protected! With package protection, in the event that your package is lost, stolen, or damaged while in transit, we will replace it free of charge. To start a shipping claim, please click here.

Need Assistance?

If you have any concerns about shipping costs or transit times, or if you notice discrepancies during checkout, feel free to reach out to us at sales@jdmuscleusa.com. We’re happy to assist you and ensure a smooth delivery experience.

Our policy lasts 30 days. If 30 days have passed since your purchase, unfortunately, we can’t offer you a refund or exchange. To initiate a return, please email us at sales@jdmuscleusa.com.

Eligibility for Returns

✅ Items must be unused and in the same condition as when received.
✅ Items must be in their original packaging.

Non-Returnable Items

❌ Gift cards
❌ Special-order or custom products

How to Initiate a Return

📧 Include the following details in your return request email:

Order Number

Item(s) to be returned

Reason for return

Important Notes:

Do NOT send your purchase back to the manufacturer.

Do NOT return any items without first setting up a return request with us.

Partial Refunds

Partial refunds may be granted under the following conditions:

⚠️ Items not in original condition, damaged, or missing parts not due to our error.
⚠️ Items returned more than 30 days after delivery.

Restocking Fees

Some manufacturers may charge a restocking fee, which includes but not limited to:

ManufacturerRestocking Fee

ESR30%

JDMuscle15%

PLM & Option Lab 20%

Cancellations

Before placing an order, please confirm availability.

Cancellations within 7 days may be subject to fees to cover third-party transaction costs.

Once the order has been processed (packaged or tracking generated), cancellations are not allowed. Eligible items may be returned instead.

Special-order items cannot be canceled.

Refund Process

🔄 Once your return is received and inspected, we will notify you of the refund status.
💳 Approved refunds will be credited back to your original payment method within 3-10 business days (depending on the payment provider).

Late or Missing Refunds

🔍 Check your bank statement — sometimes the refund may not appear as a new entry but as the disappearance of the pending charge. 📞 Contact your credit card or financing company — they may require additional time for processing.

If you’ve done all of the above and still haven’t received your refund, email us at sales@jdmuscleusa.com for assistance.

Sale Items

Only full-priced items are eligible for returns and refunds.

Exchanges

We replace items only if they are defective or damaged. To request an exchange for the same item, email us at sales@jdmuscleusa.com.

Gifts

🎁 If the item was marked as a gift when purchased and shipped directly to you, you will receive a gift credit for the return value.
📩 If the gift giver had the item shipped to themselves, we will refund the gift giver.

Return Shipping

📦 Customers are responsible for return shipping costs unless the item is damaged, defective, or incorrect (in which case we will cover shipping both ways).

Initial shipping costs are non-refundable.

Return shipping costs will be deducted from the refund amount.

For items over $75, consider using a trackable shipping service or purchasing shipping insurance. We are not responsible for lost or damaged items during return shipping.

Return Shipping Address: Please use the address provided in the RMA/return instructions, as it may differ from the initial shipping address.

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