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How Many Oxygen Sensors are in a Car?

Published Thu February 16, 2017

oxygen sensor


The oxygen sensor is a car part that you probably never think much about. In fact, you may be unsure of what it even does, yet it is essential for your vehicle to function normally or perform optimally.

An oxygen sensor, which is sometimes abbreviated as an O2 Sensor, generates a reading based on the oxygen level within the automotive exhaust system. The oxygen sensor is made of ceramics and includes a number of pores, which are electrodes coated in platinum and surrounded by a threaded casing. The sensor is effectively screwed into the exhaust pipe with half of it sticking out. Most sensors undergo a heat test, which ensures they can reach their optimal operating temperature promptly.


How Many Oxygen Sensors Does A Car Have?


In short, it varies from one vehicle to the next. The reason for this is pretty simple. All new vehicles sold in the United States are required to have catalytic converters in each exhaust pipe. These catalytic converters take harmful gasses and turn them into less harmful gasses. Every catalytic converter is required to have a couple of oxygen sensors.

So if you have a single exhaust system, you probably have one catalytic converter and, thus, two oxygen sensors. Cars with double exhaust pipes, meanwhile, will be fitted with a total of four oxygen sensors.


Where are O2 Sensors located?


The dual oxygen sensors within an exhaust pipe can detect the cleanliness of the exhaust before it enters the catalytic converter, and then compare it to the cleanliness of the exhaust as it leaves.

The sensors help ensure the optimal performance of your vehicle.  Your vehicle’s engine control unit (ECU), which is essentially its computer, uses this information to function properly. A potential problem is that unburned hydrocarbons passing through the ECU can ultimately burn out the oxygen sensors and the catalytic converters. This can lead to potentially costly repairs.


How Do You Care for Your Oxygen Sensors?


The good news is, there are actions you can take to extend the lifespan of your oxygen sensors. The first step is to steer clear of discount, low-quality gasoline. Also, make sure to check your owner’s manual and see what the manufacturer recommends in terms of fuel octane and avoid using any fuel with a lower octane level.

Finally, make sure you’re having your vehicle serviced regularly, especially paying attention to air filters and spark plugs. Replacing these parts is much easier and more affordable than replacing your oxygen sensors or your catalytic converter!

By taking your vehicle in for routine maintenance, you’ll hopefully never have to worry too much about your oxygen sensors.