Hello San Diego! Did you know that the first federally-mandated emissions control device was introduced in the 1960's? The Positive Crankcase Ventilation valve, or PCV valve, has been installed in CA vehicles since 1964 and represents the first legislation by the United States government to regulate harmful emissions as well as to improve performance in the country's vehicles.The PCV valve, as you can probably guess, is located on the crankcase. The crankcase is the lowest part of a vehicle's engine. It houses the crankshaft and the engine oil. The crankshaft connects to the pistons that power the engine.Pistons are pushed down when fuel is burned in an engine. This causes the crankshaft to rotate, which sends power to the transmission.  It ultimately turns the axles and causes the vehicle to move. Some of the gases released by the burning fuel squeeze around the pistons and down into the crankcase.If the escaped gases mix with the engine oil in t ... read more