You see, it is a proven fact that during the combustion cycle of an engine, a small amount of that combustion gas is passed into the crankcase which is commonly referred to as blow-by. Without an efficient way to vent this excess oil, it is usually rerouted back to the intake. This oil can gunk up your intake system, and by installing a quality catch can you can help prevent these unwanted contaminants from being introduced into your intake.