Oxygen Sensor

Installed on the three-way catalytic converter, oxygen sensor is a key component that realizes the closed-loop control of gas mixture (gas-air mixture) in order to reduce the pollutants in vehicle exhaust. When the ratio of gas and air into the engine cylinder deviates from the theoretical air-fuel ratio, the engine combustion will deteriorate and the pollutant emission will increase. At this moment, the three-way catalytic converter cannot purify all of the CO, HC and NOx in the exhaust and thus result in excessive vehicle emissions. Therefore, an oxygen sensor is installed on the three-way catalytic converter to detect the oxygen concentration in the exhaust. Simultaneously, the sensor sends a feedback signal to the ECU; then, the ECU controls the injection by fuel injector of fuel injector and the air intake of engine so that the air-fuel ratio of the gas mixture can be controlled around the theoretical value.

Product Introduction

Masuma oxygen sensor adopts high quality plate chip and advanced ceramic technology. Compared with the traditional finger-type oxygen sensor, it shortens the time for the product to reach the normal operation temperature. Therefore, it can reduce the vehicle emissions during the cold start phase. The product is configured with a integrated heater in which the multi-layer sensing elements can maintain accurate performance after long-term service.

Schematic Diagram of Product Structure

Maintenance Tips

Check the work status of oxygen sensor for each 30,000 km. If aging or failure occurs, please rinse or replace oxygen sensor in time. Do not try to save a little but lose a lot because the performance of both three-way catalytic device and engine will be damaged due to the abnormal operation of oxygen sensor.

Avoid collision of oxygen sensor with hard object.

Oxygen sensor contains sensitive ceramic elements. If it collides with hard objects, the violent vibration and impact may destroy the ceramic elements or heating elements inside. Therefore, please avoid the collision of oxygen sensor with hard object.

Do not drag the oxygen sensor wire.

Oxygen sensor belongs to a highly precise sensor. Therefore, dragging the sensor wire may cause an unreliable connection of oxygen sensor and thus affect its operation.

Do not rinse the exhaust pipe after flameout.

Please do not rinse the exhaust pipe immediately after the engine stops operating. When the exhaust pipe is cooled drastically from the outside, the sensitive ceramic element of oxygen sensor will burst, and the oxygen sensor will be damaged.

Maintenance Diagram:

I. Oxygen Sensor Disassembly

1. The oxygen sensor is usually disassembled by special socket spanner.

2. Loosen and disconnect the thermal oxygen sensor connector.

3. Remove the thermal oxygen sensor from the front exhaust pipe by special socket spanner (See the diagram).

II. Oxygen Sensor Assembly

1. Clean the joint surface between the thermal oxygen sensor and the front exhaust pipe.

2. Apply the sealing grease to oxygen sensor, then install the sensor by special tools, and tighten it to 55 N·m.

3. Connect the thermal oxygen sensor connector.

4. Connect to the ground terminal of accumulator.

III. Precautions for Oxygen Sensor Assembly and Disassembly

1. The special sleeve must be installed to the root of oxygen sensor and then loosened forcibly. Otherwise, the sensor thread may be worn out.

2. When loosening the sleeve, please pay attention to the wiring harness on the oxygen sensor, and then loosen it forcibly after the special sleeve is well installed. Simultaneously, please do not turn the wire harness to end at one try because the wire harness is easy to deform and even break down. After loosening, please turn back and forth to adjust the angle, so as to protect the wire harness.

3. The special sleeves also vary upon size. Please confirm the oxygen sensor installation size before your purchase.

Installed on the three-way catalytic converter, oxygen sensor is a key component that realizes the closed-loop control of gas mixture (gas-air mixture) in order to reduce the pollutants in vehicle exhaust.