Car Basics: How Does An Oxygen Sensor Work?

How Does An Oxygen Sensor Work

Today’s cars are more sophisticated than the cars back in the day. And as a car owner, it’s a given to have basic knowledge of your vehicle. Who else should know it than its owner, right? 

Basic knowledge of components in your cars, like engine oil, plug welds, vehicle fluid, and tire pressure, is a must. Now with a modern vehicle, you have to add knowledge of other technical stuff, such as oxygen sensors.

Various sensors are used in today’s cars to determine the optimal engine performance, fuel efficiency, and other essential aspects. The oxygen sensor, for one, plays a crucial role in determining the performance of a vehicle’s engine. In your car, oxygen sensors serve several purposes. 

This article explains what oxygen sensors are, how they work, why they are critical to your vehicle’s performance, and how you can maintain or resolve concerns regarding wear and malfunction.

What Is An Oxygen Sensor?

An electronic device, the oxygen sensor is designed to measure the amount of oxygen (O2) in liquid or gas. In essence, it makes modern electronic fuel injection and emission control possible. 

It’s used most commonly to determine the air-fuel ratio and, if necessary, adjust it dynamically to ensure that catalytic converters in cars and other vehicles work at their best. 

Additionally, it’s helpful when it comes to checking whether a converter is working correctly. An oxygen sensor typically produces up to 0.9 volts when there is little unburned oxygen in the exhaust and the fuel mixture is rich.

There are two types of oxygen sensors: the universal exhaust gas and the binary exhaust gas oxygen sensor. 

1. Universal Exhaust Gas

This sensor accurately determines the ratio of inadequate to excessive air or fuel. In addition, it is suitable for gas and diesel engines because it offers a broader range of calculations.

2. Binary Exhaust Gas Oxygen Sensor

Binary sensors transition electrical voltage at 350 °C, depending on how much oxygen is in the exhaust. In order to distinguish between a lack of air and an excess of air, the oxygen level in the exhaust must be compared to the ambient air oxygen level.

How Does An Oxygen Sensor Work?

Oxygen sensors are installed in exhaust pipes to distinguish between rich and lean mixes. Most sensors use a chemical reaction to produce voltage. Oxygen sensors and engines constantly communicate to assess whether fuel is burning lean (too little oxygen) or rich (too much oxygen).

By detecting the voltage in the mixture, the engine’s computer adjusts how much gasoline goes into the engine based on whether the mixture is lean or rich.

For instance, when the air/fuel ratio is high, a small voltage will be generated (800-1000mv). If the air/fuel ratio is lean (100-200mv), it will produce much less power.

Since the amount of oxygen that the engine can draw in varies with altitude, air temperature, engine temperature, barometric pressure, engine load on the engine, the engine requires an oxygen sensor.

You can think of oxygen sensors as small generators. Since oxygen sensors need to get hot before they send signals, many sensors include internal heating devices to produce heat quickly.

The computer must assume the air/fuel ratio when the oxygen sensor malfunctions because it can’t detect it. Moreover, the car gets to consume more fuel than it should, and it becomes inefficient. 

How Do You Know When An Oxygen Sensor Is Faulty?

In most cases, the check engine light in your car indicates a problem with the oxygen sensor. Vehicles with failing sensors will have difficulty starting, move jerkily, and consume less fuel if they are not replaced. 

Other signs that your oxygen sensor is faulty include the following:

  • A code checker detects your car’s oxygen sensor
  • Your vehicle will not pass the emissions test
  • Your vehicle will have a reduction in fuel efficiency
  • Your vehicle is performing poorly, idling rough, stalling, etc.

If you’ve noticed all the signs mentioned above, then maybe it’s time to replace your vehicle’s oxygen sensors. Ignoring these signs may just put you in danger. 

Be Mindful Of Your Oxygen Sensors

Oxygen sensors are relatively robust but will deteriorate with time like many other parts. Older parts take longer to modify the correct air/fuel mixture because contaminants accumulate on the sensor’s tip. 

Maintaining a car is difficult; it may be costly, time-consuming, and exhausting. If you don’t want to deal with oxygen sensors, you can get yourself a vintage car that doesn’t have oxygen sensors, but you have to do what you must and get a regular checkup for the car. Regular checkups ensure your vehicle runs as efficiently and cleanly as possible, so make sure to do it.