Whats included Billet catch can Z-Bracket and Bolt 1/2 inch Braided Covered Hose What is the problem with your PCV system ? The Positive Crankcase Ventilation (PCV) system is used to recycle the gases that leak or “blow-by” the your engines piston rings and create a positive pressure in the crankcase. By venting these gases along with oil mist/vapor from the crankcase and route it back into the intake manifold so it can be burned off. This is a poor fix from automobile manufacturers, because over time the excess oil vapor collects along the inside of the intake tract and forms a “sludge”. This leads to a variety of issues including carbon build up, retarded timing, detonation, power loss and even engine failure.