There are two types of oxygen sensor Narrow band and wide band the narrow band will be four wires or less while the wideband most of the time will be more than four wires today the narrow band specifically the zirconia type
Producing its own Voltage :
The oxygen sensor measures oxygen levels in the exhaust system and communicates it with the ECM. It produces voltage by measuring the difference between oxygen and the exhaust system versus the atmosphere. For faster results, it needs to be heated up to 1500 Fahrenheit. The sensor controls fuel injectors to achieve the perfect air fuel ratio.
More fuel Less Air, More Air less Fuel :
For Example :
The oxygen sensor measures fuel and air conditions, with rich conditions reducing fuel and lean conditions commanding more fuel. The action sensor after the catalytic converter calculates catalytic converter efficiency. Four types of zirconia oxygen sensors are used. To test an oxygen sensor, start the engine, position the multimeter to 2 volts, connect the red lead to the oxygen sensor, and touch the black lead to a solid ground. Heat the sensor to 600 Fahrenheit and allow the car to go into closed loop. If the sensor is functioning properly, it doesn’t need replacement.
WON,T FLUCTUATE
The o2 sensor in a vehicle should stay close to 450 millivolts or 0.45V at all times, indicating a rich air fuel mixture. A reading above 550 millivolts indicates contamination, while a reading below 350mv indicates a lean air fuel mixture. To check if the sensor is faulty, use the floor on the gas pedal. To test the oxygen sensor, set a multimeter to 200 in the ohms position, disconnect the oxygen sensor, and connect one test lead to the heater terminal. If no readings are found, the heater needs to be replaced. Check for damaged wires and corrosion-free connectors to prevent oxygen sensor malfunction.
RICH CONDITION :
(MORE FUEL ,LESS AIR)
- Leaking fuel injectors
- MAF sensor
- ECT
- fuel pressure Regulator
- purge valve
LEAN CONDITION:
(MORE AIR,LESS FUEL)
- Vacuum leak
- Clogged fuel filter
- Fuel pump
- MAF sensor
- Clogged fuel injectors
- Torn brake boosted diaphragm
