Exhaust Gas Oxygen Sensor (Honda CR-V 1)

The sensor monitors the oxygen content in the exhaust gases and generates an output voltage of 0.1 V (high oxygen, lean mixture) up to 0.9 V (low oxygen content, rich mixture). The changing output voltage from the sensors is fed to the engine processor unit, which determines the ratio of oxygen and fuel in the combustible mixture. The processor unit regulates the air/fuel ratio in the mixture by setting the open time of the injectors. With a ratio of 14.7 parts air to 1 part fuel in the initial mixture, the content of harmful substances in the exhaust gases is minimal. The processor unit, together with the oxygen sensor, ensures that the composition of the combustible mixture is maintained at the specified level. The signal from a working sensor usually fluctuates between 0.1-0.3 V and 0.7-0.9 V. On vehicles since 1996, equipped with the OBD-II diagnostic system (which is an advanced OBD-I system), there are 2 heated oxygen sensors installed before and after the catalytic converter, with the 2nd sensor used only for diagnosing the converter and not for adjusting the composition of the combustible mixture. The first sensor is screwed into the exhaust pipe. The sensor starts working at high temperature. For quick warm-up (for example when starting in cold weather) on some vehicles, a heater is built into the sensor.

Dependence of the signal from the oxygen sensor on the mixture composition: 1.Voltage; 2. Stoichiometric mixture; 3. Lean mixture; 4. Air/Gasoline Ratio; 5. Enriched mixture