| 摘要 |
PURPOSE:To improve exhaust gas purifying efficiency, by a method wherein, when an engine is in a given high load running state and a given high speed running state, fuel-air mixture in an enriched air-fuel ratio is fed to a suction system. CONSTITUTION:When an engine is in a high speed running state, only an air-fuel ratio of fuel-air mixture fed to a non-detecting cylinder facing an exhaust pipe 11a, which an O2 sensor 13 is prevented from sensing, is enriched to shift a mean air-fuel ratio from a desired air-fuel ratio to the rich side. During high speed running, the temperature of an exhaust systems is increased to a considerably high value, a region, in which an air-fuel ratio is decided to be on the rich side, is increased and a feedback correction factor tends to be shifted to the lean side. This enables further improvement of exhaust gas purifying efficiency.
|
