Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. How to Replace an Oxygen Sensor

How to Replace an Oxygen Sensor

oxygen sensor

Oxygen sensors are one of the most important components on a modern vehicle’s engine management system. They are responsible for monitoring the air fuel mixture of the engine, and their readings affect important engine functions such as timing and air fuel mixture.

Over time, with normal use, oxygen sensors can begin to function with a delayed response, and they will eventually fail. Typical symptoms of a failed oxygen sensor are decreased engine performance, decreased fuel efficiency, rough idle, and in certain cases, even misfires. Usually a failed oxygen sensor will also set off a check engine light, specifying which sensor on what bank has failed.

In most cases, replacing an oxygen sensor is a relatively straightforward procedure that usually only requires a few tools. In this step by step guide, we will go over what removing and replacing an oxygen sensor typically entails.

Part 1 of 1: Replacing an oxygen sensor

Materials Needed

scanning tool

Step 1: Identify the faulty sensor. Before beginning, connect the OBD II scan tool to the vehicle and read the codes to determine which specific oxygen sensor has failed and needs to be replaced.

Depending on the engine design, vehicles can have multiple oxygen sensors, sometimes on both sides of the engine. Reading the trouble codes will tell you exactly which sensor is in need of replacing — either the upstream (top) or downstream (bottom) sensor — and on what bank (side) of the engine.

vehicle raised on jack stands

Step 2: Raise the vehicle. Once the faulty sensor has been identified, raise the vehicle and secure it on jack stands. Be sure to raise the vehicle on the side which you will allow you to access the oxygen sensor that needs to be replaced.

person disconnecting the oxygen sensor

Step 3: Disconnect the oxygen sensor connector. With the vehicle raised, locate the faulty oxygen sensor and disconnect the wiring harness connector.

person using tools to remove the oxygen sensor

Step 4: Remove the oxygen sensor. Using the oxygen sensor socket or the appropriate size open end wrench, loosen and remove the oxygen sensor.

side by side comparison of the oxygen sensor

Step 5: Compare the faulty oxygen sensor with the replacement sensor. Compare your old oxygen sensor with your new replacement to ensure the correct fitment.

new oxygen sensor installed

Step 6: Install the new oxygen sensor. Once fitment has been verified, install your new oxygen sensor, and connect the harness.

person using a scan tool to erase the trouble codes

Step 7: Clear the codes. Once the new sensor has been installed, it is time to clear the codes. Connect the OBD II scan tool to the vehicle and clear the codes.

person inserting and turning key in the ignition

Step 8: Start the vehicle. Once the codes have been cleared, remove and reinsert the key, and then start the vehicle. The check engine light should now be gone, and the symptoms you were experiencing should be alleviated.

In most vehicles, replacing an oxygen sensor is a simple procedure that requires only a few tools. However, if this is not a task you are comfortable doing on your own, this is something that any professional technician, such as one from YourMechanic, can take care of quickly and easily.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP)...
Auto Safety Tips
Driving is more than a way to get from point A to point B. Owning and driving a car can also be a highly enjoyable experience. Whether a person is driving...
P0291OBD-II Trouble Code: Cylinder 11 Injector Circuit Low
P0291 code definition When your vehicle’s PCM registers the P0291 code, it means that a voltage reading came from the fuel injector circuit – for cylinder number 11’s fuel injector –...

Related questions

Q: Check engine light on 1998 Audi A4

Any good mechanic can check them out. Here's the problem that you've got though--when there's a linking error, either the nanoport isn't working right because one of the pins is bent or there's wiring short somewhere in the computer system...

Q: 1994 Chevrolet Silverado extended cabV-8 oil pan gasket replacement?

Hi there. You would have to drain the engine oil out of the oil pan, put the plug back in the oil pan, and remove the oil pan bolts to take the pan off. Once the pan is off, you...

Q: Q: Where is the O2 sensor located?

Hi, thanks for writing in. On most Dodge, GM and Ford V-6 engines, sensor 2 bank 2 is located passenger side, rear of the engine compartment. The 2011 Dodge Charger V-6 has four O2 sensors, but this one is it'll...