PCV valves are crucial components in an internal combustion engine's crankcase ventilation system. They regulate the pressure within the crankcase by enabling controlled amounts of blow-by gases to enter the intake manifold. A faulty PCV valve can cause a number of problems, including rough idling, oil leaks, and decreased engine performance. Replacing a PCV valve is a relatively simple and inexpensive maintenance procedure that can help to improve engine performance and longevity. When considering replacing a PCV valve, important features to consider include compatibility with your specific vehicle and ease of installation.