| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a deterioration determining device for an exhaust emission control device, enabling to improve the accuracy of determining the deterioration of a catalyst to be determined when another catalyst is arranged on the upstream side of the catalyst to be determined. <P>SOLUTION: The exhaust emission control device 10 has the upstream side catalyst 11 and the downstream side catalyst 12. The deterioration determining device 1 for determining the deterioration of the downstream side catalyst 12 comprises an ECU 2. The ECU 2 controls exhaust gas flowing into the upstream side catalyst 11 to be changed over from an oxidative atmosphere into a reductive atmosphere (Steps 1, 3), uses a second equivalence ratio KACT2 and a third equivalence ratio KACT3 after change-over for executing the deterioration determination of the downstream side catalyst 12 when the upstream side catalyst 11 is in an active condition (Steps 10-21), and terminates the deterioration determination of the downstream side catalyst 12 when the upstream side catalyst 11 is in an inactive condition (Step 10). <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
