| 摘要 |
Opportunity for execution of rich control is secured whereby NO x can be removed well. An NO x storage catalyst (14) is arranged in an engine exhaust passage. When it is judged that rich control execution conditions stand, rich control is executed in order to release NO x or SO x from the NO x storage catalyst. When it is judged that the rich control execution conditions do not stand, the gear position where the rich control execution conditions would stand when assuming the gear position of a transmission (25) were changed under a constant engine output is found as a target gear position. An indicator (27) is used to display an indication that the gear position should be changed to the target gear position to a vehicle operator. When the vehicle operator changes the gear position to the target gear position and it is thereby judged that the rich control execution conditions stand, rich control is executed. |
