CONTROL DEVICE FOR ENGINE

摘要

PROBLEM TO BE SOLVED: To provide a control device for an engine determining deterioration of catalyst accurately in a short period of time.

SOLUTION: This device is provided with an engine operation state detection means 40, an air fuel ratio setting means 42 changing a target air fuel ratio in steps, an air fuel ratio control means 50 controlling air fuel ratio of mixture to be subjected to combustion to a target air fuel ratio, and a catalyst deterioration determination means determining degree of deterioration of catalyst based on response time until air fuel ratio of exhaust gas in a downstream side of the catalyst changes to a predetermined value or more toward a target air fuel ratio after the target air fuel ratio is changed in steps. A target air fuel ratio step amount setting means 41 sets the target air fuel ratio step amount based on engine operation state detected by the operation state detection means 40.

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