An oil catch can installs between your crankcase vent and intake system, replacing the traditional factory vent lines and catching oil that would otherwise enter the intake system. There are several advantages to this. First oil build up is reduced; over time oil can build up inside the turbocharger, intake manifold, intercooler, and piping - causing a 'gumming' condition. Second, a catch can prevents oil from getting in pressured turbo plumbing -- a condition that can lead to couplers blowing off under boost. Finally, oil vapor in the intake system lowers combustion temperatures and diminishes efficiency. An oil catch can gives you a little added security, makes sure you're getting the most from your mods and looks great under the hood.