A method of reducing icing-related engine misfires during operation of a vehicle is provided. The vehicle can include an engine and an engine control unit operable for at least partially controlling operation of the engine. The vehicle can further include a plurality of sensors in electrical communication with the engine control unit. The engine can include an air intake system and an exhaust system, wherein the air intake system can include a positive crankcase ventilation valve. The method includes predicting the presence of ice within the air intake system based upon an input to the engine control unit from at least one of the sensors.