JPS6416959A - Method for discriminating activation of exhaust gas concentration sensor - Google Patents

Abstract

PURPOSE:To prevent the delay in the start of the feedback control of an air-fuel ratio after restarting in the high-temp. state of an internal combustion engine by setting a prescribed voltage for discriminating activity at a higher voltage value when the engine is in the high-temp. state at the time of starting. CONSTITUTION:A sensor 4 for the opening angle of a throttle valve is connected to the throttle valve 3 ad outputs the electric signal corresponding to the opening angle of the throttle valve 3. This signal is supplied to an electronic control unit (ECU) 5. A fuel injection valve 6 is controlled in the valve opening time for fuel injection by the signal from the ECU 5. The absolute pressure signal converted to an electric signal by an absolute pressure sensor 8 is supplied to the ECU 5. A ternary catalyst 14 is disposed to an exhaust pipe 13 of the engine 1 and cleans the components such as HC in an exhaust gas. On the other hand, an O2 sensor 15 outputs the output voltage corresponding to the oxygen concn. in the exhaust gas detected by said sensor as the signal to indicate whether the air-fuel ratio is rich or lean to the ECU 5. The voltage value for discriminating the activity is set high after the starting in the high- temp. state of the engine 1, by which the discrimination of the activity of the exhaust gas concn. sensor is speeded up.