Maintaining air-fuel ratio helps with fuel economy.
02 sensors keep track of fuel mixture within a vehicle by reacting to oxygen in its exhaust that has not been burned. The sensor creates a voltage signal that goes up when air-fuel mixture gets rich and down when air-fuel mixture becomes lean.
PCM
The PCM reads the voltage signal from the 02 sensor and bases its decision on that information.Oxygen sensors (02 sensors) and the powertrain control module (PCM) of a vehicle's engine work together to maintain an automobile's air-fuel ratio. Air-fuel ratio must be maintained for a vehicle to have low emissions and good fuel economy.
02 Sensor
If it reads a signal that indicates a rich mixture, it lowers the amount of fuel being sent to the engine to make the mixture lean again. If the signal indicates a lean mixture, it increases fuel to the engine to make the mixture rich again.
False Reading
A PCM can make the wrong decisions due to a bad 02 sensor. A faulty 02 sensor may signal a lean mixture even if that's not the case. This can lead to a vehicle burning more fuel.
