| 摘要 |
An object of this invention is to accurately control an exhaust air-fuel ratio, even when a WGV (waste gate valve) is operating. An ECU 60 is equipped with a turbine passing path constant At that corresponds to a time required for exhaust gas to flow to an air-fuel ratio sensor 56 via a turbine 36a of a turbosupercharger 36, and a bypass path constant Ab that corresponds to a time required for exhaust gas to flow to the air-fuel ratio sensor 56 via a bypass passage 38. The ECU 60 calculates first and second fuel injection correction amounts Deltat and Deltab in which the path constants At and Ab are reflected, respectively. When executing air-fuel ratio feedback control, the ECU 60 selects one of the fuel injection correction amounts Deltat and Deltab based on at least an open or closed state of the WGV 40, and corrects a fuel injection amount using the selected fuel injection correction amount. It is thus possible to appropriately compensate for differences in exhaust path lengths and air-fuel ratio fluctuations that arise due to opening or closing of the WGV 40. |
