摘要 |
An ECU corrects a fuel addition interval, based on an amount of change between an exhaust gas temperature at present and a basic exhaust gas temperature obtained when a basic addition interval is set, to reduce the fuel addition interval with an increase in the amount of change in the exhaust gas temperature (steps ST1-ST4). With such correction of the addition interval, when the exhaust gas temperature is increased in a highland region or the like, the fuel addition interval is corrected to be reduced and an fuel addition amount is corrected to be increased according to the increase in the exhaust gas temperature. Thereby, an increase in a temperature at a tip portion of a fuel addition valve can be suppressed, and thus clogging of an ejection hole of the fuel addition valve with deposits can be avoided.
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