You can buy a scanner online or at most auto parts stores. If you don’t have one, you could take your vehicle to an auto parts store or mechanic to have them detect the error code.

Have a heat-resistant glove, such as a welder’s mitt. Also, put on long-sleeved clothing and safety glasses for additional protection.

Starting around 1994 and 1995, manufacturers started making vehicles with 2 oxygen sensors. The second sensor is only accessible by crawling underneath the vehicle. Lifting a car is dangerous, so make sure it is stable before looking for the sensor. If you aren’t comfortable working under a car, ask a mechanic for help.

Most vehicles made after the year 2000 actually have 4 sensors. Each vehicle has 2 sensors near the motor and 2 near the catalytic converter.

If you’re having a hard time unplugging the sensor wire, push the tab down with a flathead screwdriver as you pull the connection back with your free hand. Avoid attempting to cut and then solder the wires to the new oxygen sensor. With modern sensors, soldering causes the wires to stop working correctly.

Another way to treat a stubborn oxygen sensor is to heat up its base and threads. Use a heat gun instead of a torch to lightly warm the sensor until you can remove it. A heat gun doesn’t have flames, so it’s safer than a torch, but be careful and protect yourself with proper safety gear.

All of the tools you need are available online or at most auto parts stores. You could also check to see if your local auto parts stores has a tool rental program. If the sensor feels stuck in place, don’t force it. Apply more penetrating oil as needed to avoid damaging the vehicle. If it’s too tough to remove, take it to a professional.

You may find off-brand sensors at a cheaper rate, but avoid them for the sake of your vehicle. The only sensor model guaranteed to work with the vehicle’s onboard computer is the same one the manufacturer used. If you are able to, contact an auto parts store before attempting to change the sensor. You could also take the old sensor to a store if you can get a ride there.

To avoid any problems with the anti-seize, wear a glove when applying it by hand. If you get it on your skin, it isn’t likely to harm you, but thoroughly wash your hands afterward. You do not need a lot of the gel. As long as you get some of it into the thread grooves, the sensor will fit properly in the exhaust line.

The new sensor doesn’t have to be tightened as much as possible. In fact, overtightening the sensor could strip the threads, making it impossible to remove!

Push the plug in until it snaps into place. Make sure the cable isn’t touching the engine or other parts that heat up when the vehicle is in use.

In some vehicles, you may need to clear the check engine light manually. Shut off the engine, then turn the car’s power on using the ignition key. Use the delete feature on an OBD code scanner to reset the light. Disconnect the battery or take the vehicle to a mechanic for additional ways to shut off the check engine light. If the check engine light comes back on, either the oxygen sensor wasn’t installed correctly or your vehicle has another problem.