Plumbed into a vehicle's PCV system to capture the excess crankcase vapors, residual oil mist and moisture from reentering the intake tract
Vehicles from the factory vent these excess crankcase vapors, residual oil mist and moisture right back into the intake manifold which could cause detonation, oil deposits to form in the intake tract including the valves themselves and from lowering the efficiency of the intercooler in intercooler equipped vehicles