| 摘要 |
PROBLEM TO BE SOLVED: To provide a device that determines whether a catalyst is poisoned with sulfur while preventing complication and an increase in cost of the device.SOLUTION: The present invention relates to a sulfur poisoning determination device that determines whether a catalyst arranged in an exhaust passage of an internal combustion engine is poisoned with sulfur. The sulfur poisoning determination device includes a post-catalyst sensor that detects an exhaust air-fuel ratio on the downstream side of the catalyst, periodically detects an output variation Hr of the post-catalyst sensor, calculates an increase rate Z of the detected output variation of the post-catalyst sensor with respect to time, and determines whether the catalyst is poisoned with sulfur on the basis of the increase rate Z. |
