Patent ID: 8297040
Filing Date: 2012-10-30
Classification: B01D,F01N,F02D,Y02T

Abstract:
1. A method of operating an internal combustion engine comprising a catalytic converter, a first exhaust gas sensor that is disposed in such a way that it may be used in a lambda closed-loop control operation, and a second exhaust gas sensor that is disposed in such a way that it may be used in a trim closed-loop control operation, the method comprising the steps of: modulating a forced excitation upon an air-fuel ratio setpoint value in order to adjust a lambda variation for optimizing an efficiency of the catalytic converter, using a second exhaust gas sensor to generate a measuring signal responsive to a controlled air-fuel ratio of the internal combustion engine, a controller determining an HC quality value that is representative of an oxygen storage capacity of the catalytic converter by: the controller multiplying or adding the HC quality value and the NOx correction value to determine an NOx quality value representing a level of current NOx emissions from the engine.