| 摘要 |
An exhaust gas control apparatus for an engine, the exhaust gas control apparatus includes an addition valve for adding a reducing agent to an exhaust passage, a NOx purification catalyst, and an electronic control unit. The electronic control unit is configured to execute a control in which a transition between opening and closing states of the addition valve is made by switching between energization and energization stop of the addition valve, calculate a decrease amount of a temperature of the exhaust gas flowing out from the NOx purification catalyst with respect to a temperature of the exhaust gas before flowing into the NOx purification catalyst, when the addition valve is in the transition to the closing state, and determine that reducing agent leakage from the addition valve has occurred when the decrease amount is greater than or equal to a determination value. |
