UPRs Billet Catch Can / oil-air separator will condense and collect the oil vapor before it has any chance to reach the intake tract. As the gas and oil vapor enters UPR s can they pass through a Chambered filtering system that cools the oil vapor and gives it something to adhere to. Then the oil forms into droplets and collect in the bottom of the UPR Catch Can so that they can later be drained. This is where the additional Chambered filtering system comes into play allowing only the clean air to pass through so it can eliminate unwanted blow by. All engines have blow by otherwise there would be no need for a PCV system on your engine. PCV = Positive Crankcase Valve, which eliminates Positive Crankcase Pressure. UPR s Catch Can has become one of the most widely used and recommended cures for just about every application. The engine size and horsepower level is not relevant to the performance of the UPR Catch Can. UPR s Catch Can has become a cornerstone by improving the Performance and Economy on any vehicle you install it on.