Heated oxygen sensor ,how does one test it ?
These procedures are only for self powered conventional sensors. Some newer cars are using a different style sensor that is powered. Many oxygen sensors are replaced that are good to excellent. Many people don’t know how to test them. They routinely last 50,000 or more miles, and if the engine is in good shape, can last the life of the car. The oxygen (O2) sensor is the primary measurement device for fuel control computations in your car to know if the engine is too rich or too lean. The O2 sensor is active anytime it is hot enough, but the computer only uses this information in the closed loop mode. Closed loop is the mode where all engine control sensors including the O2 sensor are used to get best fuel economy, lowest emissions, and good power. An O2sensor is a chemical generator. It is constantly making a comparison between the oxygen inside the exhaust manifold and air outside the engine. If this comparison shows little or no oxygen in the exhaust manifold, a voltage is generated.
