Bucky brought his newest project to Crawford Performance: 2004 STI guts in a GC chassis. It was there to have an AOS installed, short for Air Oil Separator. The most important mod for your Subaru; hands down. Stock or built, it will protect your engine from excess blow-by.

What is an Air Oil Separator?
- An AOS catches any excess oil that is forced in to the intake system, and routes it back in to the crankcase of your engine.
- The system is closed loop and maintenance free, unlike a catch-can.
- Reduces Oil Consumption
- Reduces Carbon Buildup
- Maintains Efficiency, Performance, and Reliability
- Maintains Octane Levels
Read more here: https://shorturl.at/vMNTX

Although we do not offer a dedicated Air/Oil Separator kit for this kind of hybrid setup, we were able to retrofit a model meant for a 2004-2007 WRX or STI with a top mount intercooler: part number: S0714-1.
The power steering hard lines were bent out of the way to allow room, and the canister bolted right up to the strut tower.
NOTE: if you are to try this at home, use heat and never bend the same part of the line twice.