The invention relates to a new method and system for optimizing the efficiency
of an automotive catalytic converter by adjusting the engine air/fuel ratio based
on estimates of the actual amount of oxidants stored in the catalyst. An available
oxidant storage capacity of the catalyst is determined by establishing an oxidant
set point location, i.e., a location in the catalyst about which the system controls
the oxidant storage. The oxidant set point is established based on the temperatures
of the different potential set point locations and the levels of deterioration
of the different potential set point locations, as well as the oxidant storage
capacity of the emission control device system.
