Page 116 - Methods For Monitoring And Diagnosing The Efficiency Of Catalytic Converters A Patent - oriented Survey

98 Methods for Monitoring and Diagnosing the EWciency of Catalytic Converters

b) gradually increasing the air/fhel ratio correction factor while the
air/fhel ratio remains in the rich state, and gradually decreasing the
aidfhel ratio correction factor while the air/fuel ratio remains in the
lean state, or
c) delaying a time at which the aidfuel ratio changes from the rich state
to the lean state by a predetermined lean delay time, and a time at
which the aidfhel ratio changes from the lean state to the rich state
by a predetermined rich delay time.

The corresponding shifting step 4 comprises respectively the step of a),b) varying said
correction factor or c) varying said lean delay time and said rich delay time.

time

01
time

Fig. 49 (from US5282383)