Patent ID: 6553756
Filing Date: 2003-04-29
Classification: F01N,F02D,Y02T

Abstract:
A method for selecting one of first and second cylinder groups of an internal combustion engine, said first and second cylinder groups being coupled with first and second catalytic converters, respectively, wherein a first air/fuel ratio in said first cylinder group oscillates about a first predetermined air/fuel ratio, and wherein a second air/fuel ratio in said second cylinder group oscillates about a second predetermined air/fuel ratio, said method comprising:identifying one of said first and second catalytic converters using first and second catalyst parameters, respectively, associated with said first and second catalytic converters; and, selecting one of said first and second cylinder groups coupled to said identified catalytic converter for phase shifting air/fuel ratio oscillations in said selected group, said selection being made to reduce engine emissions during said phase shift.