All engines use a sealed PCV system that does not allow fresh air into the crankcase. This means the crankcase is under vacuum at all times and any leak in the system is a vacuum leak. It is important to make sure all hoses are in good condition and the dipstick is firmly sealed in the tube. No other maintenance is required, though visually checking the system for damaged hoses and leaks is recommended.
The fuel evaporation system consists of an expansion tank, carbon canister, fuel filler cap, solenoid activated purge valve and connecting lines and hoses. The filler cap is a check valve that allows air into the tank but will not allow vapors out. No scheduled maintenance is required, though visually checking the system for damaged hoses and leaks is recommended.