The NISMO RB26DETT Engine Parts - Oil Separator is the perfect way to protect your car`s delicate air intake system. Blow-by gas exciting the combustion chamber can mix with engine oil and return during intake stroke. While under normal conditions oil collects in the intercooler, blowback can cause parts related to intake, such as the airflow meter, to become dirtied by oil. The NISMO oil separator separates the oil from the back blow gasses returning from the cylinder head during the intake stroke, decreasing the amount of oil deposited in the intercooler. Because it is designed to return the separated oil to the oil pan, the oil separator also decreases motor oil consumption. The blowback gases are returned to the engine and are not released to the atmosphere, making this a valuable device for automobile inspection procedures. Nismo is the best for anything Nissan and is the top choice of all major Nissan tuners out there!