| 摘要 |
PROBLEM TO BE SOLVED: To perform sulfur poisoning recovery control while making compatible fuel economy and drivability.SOLUTION: In the case that a sulfur poisoning recovery requirement is issued to an NSR catalyst 15 connected to a cylinder of a right bank 11, and a recovery unnecessary requirement in which the recovery of sulfur poisoning is not required is issued to a left bank 21, an ECU 50 performs first poisoning recovery control to a recovery requirement bank (right bank 11) when a recovery non-requirement bank (left bank 21) is in a lean operation. By the first poisoning recovery control, the recovery requirement bank is controlled to a non-combustion cylinder (fuel cut cylinder) and a rich combustion cylinder. On the other hand, when the recovery non-necessary bank (left bank 21) is in a stoichiometric operation or a rich operation when there is the sulfur poisoning recovery requirement, second poisoning recovery control is performed to the recovery requirement bank (right bank 11). By the second poisoning recovery control, the recovery requirement bank is controlled to a lean combustion cylinder and a rich combustion cylinder. |
