CONTROL DEVICE FOR ENGINE

摘要

PROBLEM TO BE SOLVED: To provide a control device for an engine capable of speedily and highly precisely determining deterioration of a catalyst.

SOLUTION: This device is provided with a first target O2storage quantity setting means 41 to attain first target O2storage quantity, a second target O2storage quantity setting means 42 to attain second target O2storage quantity, and an actual O2storage quantity estimating means 43 to estimate actual O2storage quantity of the catalyst. It is also provided with a target air-fuel ratio setting changing means to change the target air-fuel ratio from the first target air-fuel ratio into the second target air-fuel ratio when the actual O2storage quantity becomes the first target O2storage quantity as the target air-fuel ratio is set at the first target air-fuel ratio, an air fuel ratio control means 51 to attain a target air-fuel ratio of for mixed gas by a target air fuel ratio setting changing means, aΔT measuring means 52 to measure desired timeΔT after the actual O2storage quantity becomes the first target O2storage quantity till the second target O2storage quantity is attained, and a catalyst deterioration determining means 53 to determine deterioration of the catalyst based on desired timeΔT measured by theΔT measuring means.

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