Originally Posted by Frankie Figs
It keeps oil out of the intake system. When your crankcase pressure is vented it gets recirculated back into the intake hose in front of the turbo then it makes its way into the IC, IC pipes, intake manifold, and then to the combustion chambers. Oil in the combustion chamber will decrease the octane of your fuel and can cause detonation (just like running 87 in your car)
You should have seen the inside of the Y-hose when I was doing my turbo swap. Black as night, and its a normally blue hose! I guess I'll hafta attack it with some "Simple Green, son!" like Franklin is always suggesting.
Catch can FTW. I'm waiting on the 2 I ordered to come in, and then I need to find a vacuum pump for the PCV.