| 摘要 |
PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine, capable of properly correcting the deviation of the output air-fuel ratio of a downstream side air-fuel ratio sensor.SOLUTION: The internal combustion engine includes an exhaust emission control catalyst 20, and a downstream side air-fuel ratio sensor 41 arranged on the downstream side of the exhaust emission control catalyst. The control device can execute fuel cut control to stop the supply of fuel into the internal combustion engine during the operation of the internal combustion engine. After finishing fuel cut control, it executes after-reset rich control to set an exhaust air-fuel ratio to be a rich air-fuel ratio. On the basis of a difference between the output air-fuel ratio and a theoretical air-fuel ratio in an output stable period Tst where a variation per unit time in the output air-fuel ratio of the downstream side air-fuel ratio sensor is not greater than a predetermined value out of a period after finishing the fuel cut control but before the output air fuel ratio of the downstream side air-fuel ratio sensor is not higher than a rich determined air-fuel ratio, the control device corrects the output air-fuel ratio of the downstream side air-fuel ratio sensor.SELECTED DRAWING: Figure 8 |
