| 摘要 |
<p>PURPOSE:To lessen the occurrence frequency of torque shocks to a a vehicle driver. CONSTITUTION:Regarding an internal combustion engine equipped with an automatic transmission 20 having a lockup mechanism 23, an NOx absorbent 18 is provided in an engine exhaust passage for absorbing NOx, when the air-fuel ratio of incoming exhaust gas is lean, and for releasing the absorbed NOx, when the air-fuel ratio of the incoming exhaust gas is at theoretical level or rich. When an NOz amount absorbed into the absorbent 18 becomes equal to or above the preset amount and the on-off selection of the mechanism 23 or a gear change is performed, the air-fuel ratio of a mixture is temporarily made rich for NOx release interlocked with the selection or the gear change.</p> |
