| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately detect occurrence of clogging of a catalyst in an exhaust emission control system of an internal combustion engine having an exhaust emission control device arranged in an exhaust passage and configured to include the catalyst having an oxidation function. <P>SOLUTION: It is judged that the clogging of a catalyst has occurred, if the temperature of the exhaust gas at the downstream side of the catalyst is lower than a specified temperature, and also if concentration of a reducing agent in the exhaust gas at the downstream side of a reducing agent adding valve and at the upstream side of the catalyst is higher than a specified concentration, when the reducing agent is added from the reducing agent adding valve arranged in the exhaust gas passage at the upstream side of the exhaust emission control device. <P>COPYRIGHT: (C)2007,JPO&INPIT |
