| abstract |
(57) [Abstract] (Correction) [Purpose] To provide a catalyst deterioration detecting device for an internal combustion engine, which can accurately judge the deterioration of the catalyst even when the O 2 storage capacity of the catalyst changes with temperature. To aim. [Constitution] The CPU 15 retrieves a deterioration judgment value corresponding to the catalyst temperature detected by the catalyst temperature sensor 13 from, for example, a judgment value table and outputs it. Further, the CPU detects the deterioration of the catalyst based on the outputs of the O 2 sensors FS and RS and the retrieved determination value. As a result, the determination value is corrected according to the temperature characteristic of the catalyst. |