Method and system for compensating for degraded pre-catalyst oxygen sensor in a two-bank exhaust system
US6282888A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 20, 2000 |
| Grant date | Sep 4, 2001 |
| Priority date | — |
| Expiry date | Jan 20, 2020 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/1495
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A method and system for controlling the air/fuel ratio in an internal combustion engine having first and second groups of cylinders coupled to first and second exhaust banks, respectively. Each exhaust bank has a catalyst, a pre-catalyst oxygen sensor and a post-catalyst oxygen sensor, wherein the oxygen sensors monitor the air/fuel ratio in their respective exhaust banks and provide corresponding feedback signals to a controller. The controller 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 has degraded, the controller 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.