Page 142 - Methods For Monitoring And Diagnosing The Efficiency Of Catalytic Converters A Patent - oriented Survey
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124 Methods for Monitoring and Diagnosing the Efficiency of Catalytic Converters
deterioration of the catalytic converter is determined when the high frequency amplitude of the
output of the downstream sensor is large and the low frequency amplitude thereof is small.
20% purification rate ] time (sec)
Fig. 59 @om US5412942)
The method of EP0668438 (1 995) takes into consideration the differences in perfiormance of
the airhe1 ratio sensors and comprises the following steps:
