Before you start replacing the oxygen sensor, we need to identify which one to replace.
There are two oxygen sensors on 2.0T and 2.4 L four-cylinder Kia engines. One is upstream of the catalytic converter, and one is downstream.
The following tutorial will show you how to replace the upstream sensor (Bank 1 Sensor 1). The procedure is the same for the downstream O2 sensor (Bank 1 Sensor 2). You will find it easier to access the O2 sensor for the downstream sensor by getting under the car.
Start by turning off the ignition. Next, open the hood. We recommend disconnecting the negative battery terminal.
Locate the upstream oxygen sensor Bank 1 Sensor 1.
Disconnect the oxygen sensor electrical wire.
Remove the oxygen sensor using an oxygen sensor socket. To remove the sensor, you need to turn the ratchet counter-clockwise. The old sensor may be stuck. If so, use penetrating fluid to loosen up the stuck sensor.
Install the new oxygen sensor on your Kia.
Using a Kia OEM oxygen sensor, you can plug the new sensor directly into the electrical socket. If you are using a universal O2 sensor, you will need to splice and connect the wires.
Owners of Kia Forte, Optima, Rio, Sorento, Soul, Sportage, Sedona, Soul, Borrego will find this guide helpful.
The pictures below were taken on a 2016 Kia Optima equipped with the 2.4L Theta II engine, the same engine used in other Kia models and Hyundai Sonata.
This is a list of fault codes related to oxygen sensors. Note that the oxygen sensor may not always be the problem. You may have other issues, such as a bad wiring harness, for example. You can read these codes yourself using an OBD-II code reader and clear them once you complete the repair.
Here is a partial list of Oxygen Sensor related fault codes.