Patent ID: 6308697
Filing Date: 2001-10-30
Classification: F01N,F02D,Y02T

Abstract:
An article of manufacture comprising:a computer storage medium having a computer program encoded therein for an emission control device coupled to an internal combustion engine with a sensor coupled to an exhaust gas of the engine downstream of the emission control device, said computer storage medium comprising:code for providing a first output signal of the sensor indicative of a first quantity of the exhaust gas and a second output of the sensor indicative of a second quantity of the exhaust gas;code for determining a desired engine air-fuel ratio based on the second output signal;code for indicating whether said desired air-fuel ratio has changed;code for adjusting a fuel injection amount into the engine to provide said desired engine air-fuel ratio based on the first output signal; andcode for suspending said adjusting for a predetermined duration after said indication, wherein said predetermined duration is based on an oxygen storage amount of the emission control device when said desired air-fuel ratio is changed from rich to lean of stoichiometry, and said predetermined duration is based on said oxygen storage amount and a NOx storage amount of the emission control device when said desired air-fuel ratio is changed from lean to rich of stoichiometry.