Posted on: 8 January 2015
When most mechanics talk about the oxygen sensors on your vehicle, they make it sound like all of the oxygen sensors on your vehicle do the same job. However, most modern vehicles actually have two different types of oxygen sensors, upstream sensors and downstream sensors.
The Main Job Of Your Oxygen Sensors
The primary job of the oxygen sensors on your vehicle is to send information to the emission control system. Your oxygen sensors communicate information to the emission control system and let the system know how much oxygen is present in the exhaust. The emission control system uses this information to adjust how much fuel it releases into your engine for combustion. Your oxygen sensors are just one of the many components that work together and allow your engine to run smoothly.
The Job Of The Front Or Upstream Oxygen Sensor
Many older vehicles only have upstream oxygen sensors. Most vehicles made since the 1990's have both an upstream and a back stream oxygen sensor.
The upstream oxygen sensor is generally located right before the catalytic converter. This positioning allows the oxygen sensor to read the oxygen and fuel levels that are being released from the exhaust pipe. This information is then sent to the emission control system. If the oxygen sensor readings show that there is too much fuel in the emission, the control system will reduce the amount of fuel that is being released. If the oxygen sensor readings show that there is not enough fuel in the emissions, the control system will increase the amount of fuel that is being released into the engine.
This oxygen sensor helps the emission control system keep the air and fuel ratios in balance.
The Job Of The Rear Or Downstream Oxygen Sensor
You will only find downstream or rear oxygen sensors in newer vehicles that have been produced since the late 1990's. You will find the rear oxygen sensor right after the catalytic converter. The rear oxygen sensor measures the levels of pollutants that are coming out of your exhaust pipe.
Ideally, if the catalytic converter is working correctly, the reading between the front oxygen sensor and the rear oxygen sensor should be different. The catalytic converter should remove many of the pollutants from the exhaust before it is released into the atmosphere.
However, if the readings between the two are the same, then the catalytic converter may be going out. This can trigger your vehicle's check engine light to come on.
Most vehicles made after the late 1990's have two different types of oxygen sensors. The upstream or front oxygen sensor is responsible for helping the emission control system release the right amount of fuel and air into the engine. The downstream or rear oxygen sensor is responsible for monitoring and ensuring that the catalytic converter is working properly and removing pollutants from the exhaust. If your mechanic tells you that you need to replace your oxygen sensor, make sure you understand which sensor needs to be replaced. For more information, contact a shop such as Slipstream Autocare.Share