The
PCV Valve is an important part of a car's emissions control system.
The PCV valve takes unburned gases that have escaped the combustion
chambers by slipping past the pistons into the crankcase and sends
them back into the intake manifold, where they ultimately rejoin
the air-fuel mixture and are reburned. The PCV valve essentially
recycles these escaped gases, reducing air pollution and preventing
moisture buildup inside the engine.