The PCV system is a good way of reducing hydrocarbon emissions by scavenging crankcase vapors. It circulates fresh air through the crankcase that comes in from the air intake duct to mix with blow-by gases before being pulled into the intake manifold by means of a PCV valve and vacuum in the manifold. The two main constituents of the PCV system are a pair of hoses and the PCV valve. The fresh air inlet hose begins its travel at the throttle body or air intake duct, then onto this pipe located on top of the valve cover. This combination is then taken up from beneath using an inchmanifold vacuum inch through both pressure release valves (PCV) and crank case ventilation hose (cvh). Whenever manifold vacuum is high and engine idle quality must be maintained, for instance upon engine start-up, or during deceleration, a ball and spring check-valve closes with low flows enough to restrict flow out of the crank-case through any other path than the PCV assembly into Manifold vacuum which may drop as low as 10 inches-of-mercury (in Hg). For four cylinders cars you can disconnect fresh air inlet hose from throttle body or air intake duct or remove it from valve cover. When you want to disconnect it from pcv valve or intake manifold just pull off Crankcase Ventilation Hose. In Sportage V6 models, loosen both ends of fresh air inlet hose and crank case ventilation hose so that they can be removed easily. Remove the PVC valve from front Valve Cover.