Crawford FMIC Air Oil Separator Black 2002-2007 WRX / 2004-2007 STI

The Crawford Air/Oil Separator effectively removes the oil from the air coming out of the engine’s ventilation system via a two-stage process:  The Crawford Performance Air Oil Separator (AOS) is the original solution to Subaru's notorious oiling system issues. Although the technology was pre-existing with other vehicle brands such as Porsche, Crawford Performance is the inventor of the first system specifically for Subaru. No other AOS on the market employs the same technology.   The first step in the process is a large volumetric swirl pot. The function of the swirl pot is to use centrifugal force to remove the oil from the air. The air is then passed through a second chamber (see second step below), and extracted through the top of the AOS. Gravity then sends the remaining oil down the walls of the swirl pot and collects in the bottom of the AOS. At this point the separated oil sitting on the bottom of the AOS is returned to a baffled chamber in the center of the engine block.  The