POSITIVE CRANKCASE VENTILATION (PCV) SYSTEM Air Cleaner Throttle Valve Orifice Blow-by Gas Fresh Air EC7038 To reduce HC emission, crankcase blow-by gas (HC) is routed through two metering orifices to the intake manifold for combustion in the cylinders INSPECTION OF PCV HOSES AND CONNECTIONS 1. VISUALLY INSPECT HOSES, CONNECTIONS AND GASKETS Check for cracks, leaks or damage. EC1636 2. CLEAN TWO ORIFICES Clean off any gum deposits in the orifices with solvent and blow out with compressed air. Orifice Orifice EC1040