Computation Efficiency Of Catalyst
The oscillation of the voltage of the Oxygen Sensors before and after catalyst is determined, rectified and averaged.
The actual quotient ARact of the voltage of the upstream oxygen sensor and the voltage of the downstream oxygen sensor is determined. Simultaneously the theoretical quotient ARtheo of these voltages is computed based on the engine load and speed.
For Diagnosis the Difference AR between the actual quotient ARact and the theoretical quotient Artheo is made.
AR = AR act - AR theo
The Difference AR expresses the efficiency of the catalyst.
Within the time of Diagnosis an adaptation matrix is completed for various engine operating points.