Patent ID: 6904751
Filing Date: 2005-06-14
Classification: F01N,F02D,Y02T

Abstract:
1. A method for controlling an internal combustion engine, the method comprising: determining a reference air/fuel ratio based on first and second exhaust gas sensors, the first exhaust gas sensor being positioned downstream relative to a first portion of a catalyst and upstream relative to a second portion of the catalyst, and the second exhaust gas sensor being positioned downstream relative to the second portion of the catalyst; determining an actual air/fuel ratio based on a third exhaust gas sensor positioned upstream relative to the first and second portions of the catalyst; determining a catalyst gain based on at least one of the first and second exhaust gas sensors and the third exhaust gas sensor; modifying the reference air/fuel ratio based on the catalyst gain; and generating a fueling command such that the actual air/fuel ratio approaches the reference air/fuel ratio.