Tomioka Racing Air Oil Separator - 1993-2011 Subaru Impreza WRX / STI / 1990-2011 Subaru Legacy / 1998-2011 Subaru Forester - Subaru EJ Engine

Tomioka Racing Air Oil Separator - 1993-2011 Subaru Impreza WRX / STI / 1990-2011 Subaru Legacy / 1998-2011 Subaru Forester - Subaru EJ Engine

The Tomioka Racing Air Oil Separator addresses a common problem on EJ-powered Subarus -- oil blow-by from the crankcase finding its way into the intake charge pipe, intercooler, and turbo inlet.

Keeping Oil Out of the Intake on EJ Subarus

The Tomioka Racing Air Oil Separator addresses a common problem on EJ-powered Subarus -- oil blow-by from the crankcase finding its way into the intake charge pipe, intercooler, and turbo inlet. The AOS is constructed from high-quality aluminum and integrates with the factory PCV system, capturing oil from the crankcase vent before it reaches the intake while automatically draining collected oil back into the factory oil pan. No manual emptying required.

Installation and Compatibility

Compatible with the factory PCV system and designed for easy installation with less hose routing than competing designs. The twist-off cap requires no tools for inspection or cleaning. Fits Subaru Impreza WRX/STI from 1993-2011, Forester from 1998-2011, and Legacy from 1990-2011 on EJ engines.

Key Features

• Air Oil Separator x 1
• 8 ft. Oil Resistant Hose x 1
• 6 in. Black Zip Ties x 10
• ½ in. Hose Fittings x 2,
• ½ in. Adapter x 1
• ½ in. Rubber Cap x 1

Fitment Notes

• Fits 1998-2011 Subaru Forester
• Fits 2002-2011 Subaru Legacy
• Fits 2004-2011 Subaru STI
• Fits 2002-2011 Subaru WRX

Straight From Subispeed

If the intercooler is collecting oil or the turbo inlet hose shows oil residue, an AOS is the correct solution. The Tomioka unit is a straightforward, well-designed piece at a reasonable price point. The auto-drain design that returns oil to the pan is the practical choice over manual catch cans for street-driven cars.

What's Included

• Tomioka Racing Air Oil Separator
• 8 ft. oil-resistant hose
• Hose fittings and adapters
• Zip ties
• Installation hardware

About Tomioka Racing

Tomioka Racing has been engineering bolt-on performance parts for Subaru platforms since 2007, with a design philosophy built around factory-style installation and real-world reliability. Every Tomioka Racing product is engineered to work with the factory setup -- clean installation, correct fitment, and durability under sustained use. For WRX, STI, BRZ, and the 86 platform, Tomioka Racing offers one of the most focused and thoroughly developed bolt-on catalogs available at this price point.