Most possible you own multiple O2 sensors in your Jeep Cherokee. Figuring out which one needs to be replaced will be more challenging than actually replacing it. A code reader can condemn and position a particular oxygen sensor, but since the sensors average around $75 or more a piece, you might consider leaving the code reading up to a professional. Most parts stores that sell quality direct-fit oxygen sensors usually have code readers and can find out the information for you at no charge as long as you purchase the part you need from them.
Once you have the required information and tools, you can change the oxygen sensor on your vehicle.
Instructions
Change the Oxygen Sensor to a Jeep Cherokee
1. Locate the oxygen sensor that needs to be replaced. The very first sensor is in the manifold and can be accessed under the hood on the driver's side of the engine. The rest will have to be accessed from under the vehicle in the exhaust system. There is one at the rear of the manifold in the front exhaust pipe, another in the pipe going to the catalytic converter on the passenger side under the Jeep.
2.3. Put on the safety glasses.4.
Raise the front of the Jeep if necessary by driving it up on car ramps. Apply the parking brake and place a wheel chock behind one of the rear tires. Crawl underneath on a creeper (if you have one) with the tools and the new sensor.
Spray WD-40 on the threads of the oxygen sensor and allow it to soak in. Be careful the engine is not too hot when replacing the sensors, especially the very front one up in the manifold.
5. Follow the wire of the oxygen sensor to the plug and unplug it. You can use the screwdriver to press in and release the clip lock.
6. Remove the oxygen sensor with the oxygen sensor socket and ratchet. If it is stubborn, you may want to try and heat the pipe area up with the hand torch to expand the pipe. Once the sensor is loosed from the threads, allow the pipe to cool down if you had to use the torch.
7. Remove the old oxygen sensor.
8. Screw in the new oxygen sensor and make sure there is a coating of anti-seize lubricant on the threads. Most quality direct-fit after-market sensors will already have a coating applied to them. This will make future extraction a little easier.
9. Tighten the sensor with the socket and ratchet, but be careful not to over-tighten. If you strip the threads of the sensor, you're going to have to buy another one.
10. Plug the wire back into the plug.
11. Remove the tools and lower the Cherokee and/or close the hood.
