| 摘要 |
An internal combustion engine system includes: a turbine disposed in an exhaust passage; a bypass passage provided in the exhaust passage and bypassing the turbine; a wastegate valve that opens and closes the bypass passage; and an air-fuel ratio sensor provided downstream of a discharge port of the bypass passage. The air-fuel ratio sensor is provided at such a position that the proportion of the amount of exhaust gas that directly strikes the air-fuel ratio sensor to the amount of exhaust gas discharged from the bypass passage changes depending on the opening degree of the wastegate valve. When the engine is in a cold-start state, the proportion of the amount of exhaust gas that directly strikes the air-fuel ratio sensor after being discharged from the bypass passage to the amount of exhaust gas discharged from the bypass passage is made smaller than when the engine is in a warm-start state. |
