| 摘要 |
PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine, capable of preventing an adverse effect due to the generation of acid liquid while achieving sulfur poisoning recovery control for causing an air-fuel ratio to be rich using an LPL-EGR mechanism.SOLUTION: In sulfur poisoning recovery control of an NSR catalyst, a return flow of EGR gas by an LPL-EGR mechanism is allowed to cause exhaust A/F to be rich (ST5) until a peak position of an SOx deposition amount inside the NSR catalyst has moved to a central part of the NSR catalyst. When the peak position of the SOx deposition amount has moved to the central part of the NSR catalyst, the return flow of the EGR gas by the LPL-EGR mechanism is stopped, and the generation of acid liquid caused by a sulfur content flowing into a low-pressure EGR passage is prevented (ST8). |
