Catalytic converter for IC engine - is monitored by sensors on input and output and with abnormality control using reference values for typical sensor readings

摘要

The catalytic converter (27) has an input sensor upstream and an output sensor downstream. The sensor outputs are monitored and provide a measure of the effectiveness of the catalytic converter in real time. The separate outputs of the sensors are compared with typical reference values to detect any abnormalities ie. to detect if either sensor is faulty. The typical values for the sensors are the central values of the sensor signals when the engine is operating at a steady rate. The control system detects the rich and lean settings of the fuel/air mixture on both sensors and controls the correction for the fuel input.