Systems and Methods for Monitoring Catalyst Deactivation and Controlling an Air/Fuel Ratio

摘要

A system for controlling an air/fuel ratio in an engine based on catalyst deactivation includes an NH3 detector disposed downstream from the three way catalyst, and a subsystem that compares measured values of NH3 concentration with a nominal value of NH3 concentration at rich operating conditions. A subsystem adjusts the air/fuel ratio based on the measured value of NH3 concentration and estimated CO concentration.

主权项

1. A method for controlling an air/fuel ratio in an engine, the method comprising:
determining whether an actual value of NH3 concentration downstream from a three way catalyst is lower than a nominal value for NH3 concentrations produced at rich operating conditions; if the actual value of NH3 concentration is lower than the nominal value for NH3 concentrations produced at rich operating conditions then adjusting the air/fuel ratio based on estimated CO concentrations.