Abstract: The present invention comprises an apparatus and method for replacing an original equipment manufacturer air-oil separator apparatus having an integral pressure control valve (“OEM-AOS” system) in a vehicle. The OEM-AOS system is disconnected from the engine air intake. The integral pressure control valve is disabled. An accumulator for collecting oil from by-pass combustion gas is connected to the OEM-AOS system. A discrete pressure control valve (“discrete-PCV”) is connected to the accumulator and to the engine air intake. The discrete-PCV is located within the vehicle at an easily accessible location so that it can be quickly accessed and replaced when necessary. The accumulator includes a sensor that is operable to send a warning signal to a vehicle operator when the vehicle needs to be serviced to remove condensed oil from the accumulator.