Method of Improving Emissions an IC Engine

A method for controlling a throttle valve 10 and an EGR valve 16 in internal combustion engine. The method comprises the steps of measuring an actual fresh mass air flow value 1 entering the engine; determining an exhaust oxygen concentration setpoint [02]spEM indicative of the oxygen concentration in the exhaust manifold; calculating an air reference value Airreference as a function of said exhaust oxygen concentration setpoint [02]spEm; determining an oxygen concentration feedback value [ 0 2] fdIM, [02]fdEM representative of the oxygen concentration in the engine; obtaining position information for the throttle valve by comparing the actual fresh mass air flow value and air reference value; obtaining position information for the EGR valve by comparing the oxygen concentration feedback value and the oxygen concentration setpoint; and controlling the throttle valve and the EGR valve according to the respectively corresponding position information. Additionally, a turbocharger 1b may be disposed in the intake manifold and pressure control inside the intake manifold is controlled based on boost pressure.