Find solution

The modern car or truck has lots of sensors to tell the vehicles computer how the engine is running, and tune accordingly. One of these is the oxygen or O2 sensor, which detects the amount of oxygen in the vehicles exhaust system and adjusts the fuel/air ration at the heads accordingly. If these sensors go out, youll see a "check engine" light on your dash until theyre replaced, and your Jeep Liberty will run sluggishly. This isnt a fun job, but it can be done in about an hour with the right tools.

Instructions

1

Lift up the vehicle using the jack and place it on jack stands. Make sure the vehicle is secure before you crawl underneath it.

2

Locate the O2 sensors on the exhaust. Theyre about 2 inches long, and have a wire pigtail sticking out of the end. These are also the only sensors on the exhaust, and the only wiring thats near the exhaust at all.

3

Unplug the O2 sensor from the vehicle wiring harness using your hands.

4

Remove the O2 sensor using the 3/8-inch ratchet and the oxygen sensor socket. Then thread the replacement O2 sensor in place and tighten it down using the 3/8-inch ratchet and the oxygen sensor socket.

5

Plug the O2 sensor back into the stock harness using your hands. Repeat the process for the other O2 sensors in the exhaust, then lift the vehicle back up and remove the jack stands using the jack.

A vehicles Powertrain Control Module adjusts the ratio of air and fuel so a vehicle gets the best possible fuel economy. This 02 sensor constantly signals the PCM to inform it of the status of the air and fuel mixture. More than one type of 02 sensor is available for installation.

Zirconia

The most common 02 sensor is the zirconia type; it comes in either heated or unheated versions. Unheated zirconia 02 sensors take a few minutes to work, because they rely on a vehicles exhaust to heat up before they produce a signal. Heated zirconia 02 sensors have a heater circuit inside them. They work in about 60 seconds or less.

Titania

Titania 02 sensors are made up of a different type of ceramic than that found in zirconia 02 sensors. It uses resistance changes to notify the PCM. Only a few vehicles come equipped with Titania 02 sensors.

Wide-band

The signal produced by wide-band 02 sensors switch in direct proportion to the ratio of the air and fuel mixture. The PCM keeps a constant air-to-fuel ratio just by adding or taking away fuel when needed.

Your 1997 Ford Explorer has two oxygen sensors built into the exhaust system. The oxygen sensors monitor the amount of oxygen in the exhaust to help the truck regulate how much fuel it burns. When an oxygen sensor fails, your truck may burn more fuel than necessary, reducing your fuel mileage drastically. You can replace the oxygen sensors quickly in your own driveway. Buy new sensors from an auto parts store or a Ford dealership.

Instructions

1

Raise your Explorer with a jack and secure it on a set of jack stands. Locate the oxygen sensors on the exhaust positioned before and after the catalytic converter.

2

Disconnect the wiring harness from the oxygen sensor by pulling the connector straight off. Use an oxygen sensor socket and ratchet to remove the oxygen sensor from the exhaust pipe.

3

Install the new oxygen sensor by hand to avoid cross threading the sensor. Once the sensor is secure, tighten it with the oxygen sensor socket and ratchet.

4

Press the wiring harness connector onto the new sensor until it is secure. The wiring harness should click when it is secure.

5

Repeat the process for the second oxygen sensor if you are replacing both. Raise the vehicle with the jack and remove the jack stands. Lower the truck to the ground.