| 摘要 |
A method and system for controlling the air/fuel ratio in an internal combustion engine (12) having first and second groups of cylinders coupled to first and second exhaust banks (20,28), respectively. Each exhaust bank has a catalyst (16,24), a pre-catalyst oxygen sensor (14,22) and a post-catalyst oxygen sensor (18,26), wherein the oxygen sensors monitor the air/fuel ratio in their respective exhaust banks and provide corresponding feedback signals to a controller. The controller (202) uses the feedback signals to control the air/fuel ratio in the engine cylinders. When it is detected that one or the other of the pre-catalyst oxygen sensors (14,22) has degraded, the controller (202) calculates A/F values for the group of cylinders corresponding to the exhaust bank having a degraded EGO sensor based on feedback signals from the three still-functional oxygen sensors. <IMAGE> |
