| 摘要 |
PURPOSE:To speedily detect the anomaly and deterioration of an engine control system on the basis of the output of exhaust sensors for detecting the concentration of the exhaust harmful components in exhaust gas which are installed onto the downstream side of catalyst. CONSTITUTION:An NOX sensor 15 which utilizes SnO2 and a CO sensor 16 are installed into an exhaust system 12 on the downstream side of a three- component catalyst 14. During the air fuel ratio control by the detection signal of an O2 sensor 13, a control unit 25 reads each output signal of the NOX sensor 15 and the CO sensor 16 during the stationary operation, and compares these output values with the judgment levels corresponding to the number N of revolution and the fundamental injection time TP. When the NOX concentration or CO concentration is higher than each judgment level, the control unit 25 drives an anomaly alarm means. |
