| 摘要 |
HC feed control for feeding HC into exhaust gas upstream of an SOx trap 11 when a predetermined condition stands is executed. When an SOx trap amount is smaller than a predetermined amount, as HC feed control, first HC feed control feeding HC into the exhaust gas upstream of the SOx trap by a predetermined pattern is executed. When the SOx trap amount is larger than a predetermined amount, as HC feed control, second HC feed control feeding HC into the exhaust gas upstream of the SOx trap by a pattern different from the predetermined pattern, which pattern keeping the temperature of the SOx trap from locally becoming higher than the predetermined temperature or suppressing the formation of a region in the exhaust gas flowing into the SOx trap where the air-fuel ratio becomes locally rich, is executed.
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