Method for selecting a cylinder group when adjusting a frequency of air/fuel ratio oscillations

摘要

A control system and method is provided for selecting one of first and second cylinder groups of an internal combustion engine when a frequency of air/fuel ratio oscillations in the selected cylinder group is to be adjusted. The method includes determining which of first and second frequencies of air/fuel ratio oscillations in the first and second cylinder groups, respectively, has a greater frequency. Further, the method includes selecting one of the first and second cylinder groups having the greater frequency of air/fuel ratio oscillations. The selection is made to reduce engine torque fluctuations when changing a frequency of air/fuel ratio oscillations in the selected cylinder group.