A method of operating a fuel cell stack is disclosed. The method includes operating the fuel cell stack in accordance with a predetermined profile of fuel gas/oxidant gas delta pressure vs. time, monitoring a fuel gas/oxidant gas delta pressure vs. time value of the fuel cell stack and adjusting pressure of the fuel gas by consuming excess quantities of the fuel gas in the fuel cell stack when the fuel gas/oxidant gas delta pressure vs. time value of the fuel cell stack exceeds the predetermined profile.