Air Oil Separator (AOS) - Subaru STI (VA)

Overview

This air oil separator for the VA Subaru STI stops oil from reaching the intake, where it would reduce octane and cause detonation, power loss and carbon build-up. It handles both the crankcase vent and intake filter connections in one unit, installs like an OE component, and needs no tune or setup change.

Four 5 micron coalescing filters at the inlets and outlets, plus baffling and stainless mesh, filter the crankcase air. Optional add-ons include a coolant hook-up kit to limit cold-weather condensation and a drain kit. It does not work with right-hand-drive models, and the anodized finish can fade from engine bay heat.

What's included

• Assembled AOS
• 4 Coalescent Filters
• Internal Baffling
• Stainless Mesh
• Sheet Steel Bracket for VA Chassis, LHD Only
• 3/4" Rubber Hose
• 1/2" Rubber Hose
• 3/8" Rubber Hose
• Hardware Bag, Including All Necessary Parts for a Seamless Install

Fitment

• 2015–2021 Subaru WRX
• 2015–2021 Subaru WRX STI

Options

• Color: Black, Blue, Red

Details

• Manufacturer: Verus Engineering
• Part number: A0323A
• Shipping weight: 4 lb

Installation instructions are available in the Verus Engineering install manual library.