THE GUY ABOVE TOTALLY MISSED IT. IT IS VERY SIMPLE TO REPLACE AND SHOULD COST LESS THAN $25.00.
The Positive Crankcase Ventlition(PCV) does 2 things, 1.the valve prevents backfire pressure from entering the crankcase(oil pan area), the pressure could damage oil seals and gaskets causing oil leaks. 2. as the engine runs, as small bit of combustion gases slips past the piston rings and into the crankcase, if it does not have a way out it can damage the oil seals. these gases are sent back through the engine and out the exhaust. the hoses just directs the flow of the system. the filter keeps trash from getting into the crankcase. the flow of the system is as follows:filter-hose-valve cover-crankcase- hose- PCV valve-intake manifold-cylinders-exhaust. if oil is developing in the filter, there is a clog in the system somewhere or you have bad rings