Apparatus for controlling diesel engine

An apparatus for controlling an exhaust gas is disclosed. A recirculation device (40) includes an EGR passage (41) connecting an air exhaust passage (22) with an air intake passage (16) to control the exhaust gas flowing to the intake passage (16) by opening or cloning an EGR valve (42) in the EGR passage (41) to suppress smoke caused by the exhaust gas. The apparatus includes a valve (25) disposed in the intake passage (16). The valve (25) controls the air flowing to the engine (11). The apparatus includes a speed sensor (56), a pressure sensor (59) and a gas pedal sensor (61) for detecting a driving status of the engine (11). The apparatus also includes an electronic control unit (39) for computing a target amount of the air to be supplied to the engine (11) based on the detected driving status of the engine (11). The apparatus further includes a vacuum pump (32) for controlling the intake restriction valve (25) to adjust the amount of the air based on the computed target amount. The electrical control unit (39) determines generation of the smoke based on the detected driving status of the engine (11) and corrects the amount of the air supplied to the engine (11). The electrical control unit (39) also controls the intake restriction valve (25) to increase the amount of the air with respect to the computed target amount for a predetermined time period after determining the generation of the smoke.