LINEAR AIR-FUEL RATIO SENSOR HEATER AND OXYGEN SENSOR (REAR) HEATER CONTROL





The linear air-fuel ratio sensor and the oxygen sensor (rear) respond slowly when the exhaust gas temperature is low. Therefore, the sensor responsiveness is improved by applying the electrical current to the heater to heat sensors within the exhaust gas low temperature range, such as immediately after the engine is started with low exhaust gas temperature, or while the warm-up is being performed, and when the fuel is cut at the deceleration. In accordance with the operating conditions or activation conditions of the linear air-fuel ratio sensor and the oxygen sensor (rear), the engine-ECU changes the duty ratio of the heater. The control is performed so that the linear air-fuel ratio sensor and the oxygen sensor (rear) can be activated more quickly.