| 摘要 |
PROBLEM TO BE SOLVED: To attain both warming up of catalyst warming up and prevention of misfire during lean imbalance.SOLUTION: When engine starting is the first time from system startup, cooling water temperature Tw is not more than a threshold value Twref and lean imbalance occurs, catalyst warming up is conducted if catalyst prediction bed temperature Tcat is less than a threshold value Tref2, and it is not conducted if the catalyst prediction bed temperature Tcat is not less than a threshold value Tref2 (S130-S180). Thus, when compared with such a state that catalyst warming-up control is executed even when the catalyst prediction bed temperature Tcat is not less than the threshold value Tref2, the catalyst warming up necessitates a little more time, however, the deterioration of emission due to misfire caused by the execution of catalyst warming up can be prevented, and the degree of entire deterioration of emission be also prevented. As a result, both catalyst warming up and prevention of misfire can be attained. |
