| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To improve the diagnostic accuracy of a deterioration condition by knowing deterioration causes in an exhaust emission control catalyst. <P>SOLUTION: A catalyst diagnostic device diagnoses the deterioration condition of the exhaust emission control catalyst 1 which carries adsorptive material in an exhaust passage of an internal combustion engine for adsorbing or discharging toxic substances in exhaust gas. An O<SB>2</SB>sensor is installed on the exhaust passage and interposed between the device and the exhaust passage for detecting an oxygen concentration condition in the exhaust gas, and the device estimates a scattering amount of kalium from the exhaust emission control catalyst 1 from output of the O<SB>2</SB>sensor when the exhaust gas is in reduction atmosphere and diagnoses the deterioration condition of the exhaust emission control catalyst based on the scattering amount of kalium. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
