Q: What is the function of the Positive Crankcase Ventilation (PCV) system and when should you consider checking and replacing PCV Hose and PCV Valve?A: The Positive Crankcase Ventilation (PCV) system reduces hydrocarbon emissions by directing blow-by gases and crankcase vapors into the intake manifold. Fresh air from the air filter housing mixes with these gases in the crankcase before exiting through the PCV valve. During idle and part-throttle conditions, blow-by gases flow through the PCV valve into the intake manifold, while fresh air is drawn into the crankcase. Over time, sludge buildup may reduce the system's efficiency and cause leaks. Regular checks and possible replacements of the PCV valve and hoses during routine maintenance are recommended.