Perrin Air/Oil Separator | 2008-2014 Subaru WRX and 2008-2019 Subaru WRX STI

2008-2014 Subaru WRX and 2008-2019 Subaru WRX STI with TMIC Air/Oil Separator by Perrin The PERRIN Air Oil Separator is not a catch can. Catch cans capture engine blow-by and stores it in a container, which requires constant attention and removal of oil every few hundred miles. The air oil separator separates the oil from the air, draining it back to the engine, which eliminates the need for constant attention and draining of oil. As oil drains from the bottom of the PERRIN Air Oil Separator, clean oil-free air vents out of the top to rejoin the intake tract. The PERRIN Air Oil Separator features swirl pot technology and multi-layer baffles. This design forces incoming engine blow-by to move rapidly across the baffles, separating oil from the engine blow-by. Multiple layers of baffles means more surface area to collect more oil, making for a compact and efficient design. Oil entering from the crankcase vents spins counter clockwise through the entire body of the AOS, passing along fou