The COBB Air/Oil Separator (AOS) is engineered to integrate seamlessly within the crankcase ventilation system of the Ford Focus ST, effectively preventing oil vapors from contaminating the intake system. This component has undergone extensive design refinement to ensure a hassle-free installation while maintaining compatibility with third-party emissions systems.
The AOS features a factory breather plate coupled with a custom spacer plate crafted from 33% glass-filled nylon, ensuring a precise fit. The assembly is injection molded for optimal alignment, while the COBB oil drain plate is positioned between the OEM air/oil separator and the engine block. This setup utilizes an OEM gasket provided by COBB to guarantee a leak-free seal.
This Air/Oil Separator operates in series with the original PCV circuit, directing crankcase air through a swirl pot and a series of baffles. This design promotes the condensation of heavier oil particles in the blow-by vapor, allowing them to collect as liquid at the base of the canister. A dedicated drain line channels this liquid back to the crankcase, ensuring that oil particles do not re-enter the intake manifold.
By utilizing this drain-back system, the COBB AOS keeps the intake valves cleaner and minimizes the risk of detonation, contributing to a more robust engine capable of higher output with reduced maintenance. Oil vapors can diminish fuel octane ratings and lead to carbon buildup, making this separator a practical upgrade for maintaining engine health.
A Sound Symposer Delete is required for the installation of this AOS. If not already equipped, consider adding the COBB Sound Symposer Delete Kit for a complete setup.
For installation instructions, click here.
⚠ WARNING:
Cancer and Reproductive Harm
https://www.P65Warnings.ca.gov
| Vehicle Make/Model | Year | Trims |
|---|---|---|
| Ford Focus | 2013-2017 | ST |
| Scion FR-S | 2013-2016 | Base |
| Subaru BRZ | 2013-2019, 2022-2025 | Premium |
| Subaru BRZ | 2013-2020, 2022-2025 | Base |
| Subaru BRZ | 2013-2020, 2022-2025 | Limited |
| Subaru BRZ | 2013-2020, 2022-2025 | Sport-tech |
| Subaru BRZ | 2015 | Aozora Edition |
| Subaru BRZ | 2015 | Series.Blue |
| Subaru BRZ | 2016 | Series.HyperBlue |
| Subaru BRZ | 2017 | Series.Yellow |
| Subaru BRZ | 2018, 2020, 2024-2025 | TS |
| Subaru BRZ | 2018-2020 | Sport-tech RS |
| Subaru BRZ | 2019 | Series.Gray |
| Subaru BRZ | 2023, 2025 | Limited EyeSight |
| Subaru BRZ | 2025 | tS EyeSight |
| Toyota 86 | 2017 | Special Edition |
| Toyota 86 | 2017-2020 | Base |
| Toyota 86 | 2018-2020 | GT |
| Toyota 86 | 2019 | TRD Special Edition |
| Toyota 86 | 2020 | Hakone Edition |
| Toyota GR86 | 2022-2025 | Premium |
| Toyota GR86 | 2022-2025 | Base |
| Toyota GR86 | 2023 | 10th Anniversary Special Edition |
| Toyota GR86 | 2024 | TRUENO Edition |
| Toyota GR86 | 2025 | Hakone Edition |
COBB Tuning Products, LLC warrants to the original retail purchaser that all components manufactured by COBB Tuning, or sold under the COBB brand, and purchased directly from COBB Tuning or from an Authorized COBB Tuning dealer hold a 12-month limited warranty from the date of purchase against defects in materials and workmanship ("Limited Warranty"). This Limited Warranty extends only to the original retail purchaser of the component. This Limited Warranty is intended to cover components only when they are used in the manner for which they were originally designed. This Limited Warranty is void on all products found to have been used in racing or off-road applications, of any nature whatsoever, and on all products that show evidence of abuse, lack of proper maintenance, improper installation, misapplications, alteration in any way whatsoever from their original design or negligence in the use of COBB Tuning products. This Limited Warranty does not cover normal maintenance or wear items such as belts, brake pad material, clutch disc friction material, and brake rotors. COBB Tuning accepts no responsibility for any special, incidental, or consequential damages or costs or grievances incurred by failure of a COBB Tuning component, including but not limited to labor and shipping costs. All implied warranties shall be limited in duration to the said 12-month warranty period and shall be limited to the express terms and provisions of this Limited Warranty.
PROCEDURES FOR WARRANTY CLAIMS
In the event a problem occurs with a COBB component, please contact COBB Tuning at 866-922-3059 during our normal business hours. When speaking to a customer representative, you will need to have your invoice number on hand. The following steps will then be followed: 1. COBB representative will determine if product will have to be returned to COBB Tuning for inspection. A RMA number will be given to be placed clearly on the shipping label. 2. The retailer or the customer will ship the component in question back to COBB Tuning, including the original sales receipt and a clear description of the exact problem experienced. It is the responsibility of the retailer or the customer to pay for shipping back to COBB Tuning. 3. If COBB finds the component to be defective and within the warranty period, COBB will repair, replace, or issue credit to the customer at COBB's option. Any repaired or replaced product will be returned to the retailer or customer, freight prepaid via ground or by truck. Please note that no replacement warranty parts can be shipped until original parts are returned to COBB tuning for inspection.