| 摘要 |
<p>PURPOSE:To improve the deterioration deciding accuracy of each exhaust sensor, and to prevent the increase of exhaust of a harmful component in the exhaust gas, by deciding the deteriorating condition of a catalyst by the average value of a standard comparison value, while correcting a specific execution timing by the standard comparison value. CONSTITUTION:The deteriorating condition of a catalyst 40 is detected by the response delay times of the detected signals of a front O2 sensor 38 and a rear O2 sensor 44. When an internal combustion engine 2 is started, the program is started in Step 202, in a control means 114, and the confirmation whether the 02 sensor deterioration condition is accomplished or not, and its deciding are carried out in Step 204 and 206. When it is accomplished, the delay time for exhaust sensor rich/lean deciding, a feedback correcting amount, and the like are measured, so as to find a standard comparison value, in Step 208 and the latter, and a specific execution timing is corrected by the standard comparison value, while the average value of the standard comparison value by measuring in specific rounds is calculated, and the deteriorating condition of the catalyst 40 is decided by the average value.</p> |
