| 摘要 |
Provided is an internal-combustion engine (10) having an oxidizing catalyst (52) provided in an exhaust passage. The air/fuel ratio of an air/fuel mixture is oscillated, relative to a target air/fuel ratio, in a preset amplitude lean or rich of the stoichiometric air/fuel ratio. Referring to the temperature of the catalyst as the catalyst temperature, the amplitude set in relation to the catalyst temperature is adopted as the preset amplitude, and the amplitude set when the catalyst temperature is higher than a preset temperature is smaller than the amplitude set when the catalyst temperature is lower than the preset temperature. |
