Fiesta ST Oil Catch Can kit:

The Damond Motorsports Oil Catch Can kits come with everything needed for an optimized Oil Catch Can system. An oil catch can is, in a sense, a filter for the positive crankcase ventilation system. The oil catch can(OCC for short) is used to tap and contain blow-by oils and condensed crankcase gases, that would otherwise flow throughout the PCV system back into the intake tract, and allows for draining of these fluids remotely. With the addition of an OCC kit, blow-by oils and gasses are routed to the OCC, allowing them to be captured. This prevents the blow-by from entering the intake system, where it would otherwise contaminate the clean air entering the engine. Cleaner air leads to better combustion, more power, better fuel economy, less detonation, and less oily build-up on the valves.