GrimmSpeed Air Oil Separator Red WRX (2002-2007) STI (2004-2018) Mazda four-layer cotton-gauze filter that features

four-layer cotton-gauze filter that features a redesigned air horn for improved performance

These solid polyurethane Whiteline bushings for the Subaru are much harder compared to the OEM units

3" blue titanium tips

and was designed for both drivability and performance

GrimmSpeed Air Oil Separator Red WRX (2002-2007) STI (2004-2018) Mazda four-layer cotton-gauze filter that featuresGrimmSpeed has a unique design for the Subaru WRX, STI and Legacy GT which allows you to keep your PCV valve while separating the oil out of the crankcase and head ventilation air. None of the other competitors on the market are able to vent both. The unit is very compact and efficient, it bolts directly on to the factory oil cap location. You will no longer have to keep tabs on your oil level and or empty the catch can like on most standard cans as