How to Replace the O2 Sensor on 2001 to 2005 Explorer Sport Tracs

In 2001, Ford released an all-new style of SUV into its lineup, the SUV-pickup hybrid Explorer Sport Trac. The first generation of the Explorer Sport Trac lasted through the 2005 model year. The first generation of Explorer Sport Trac came with a 4.0-liter V-6 that produced 205 horsepower in 2001 and 210 horsepower in the remaining four years. All 2001 through 2005 Explorer Sport Tracs had four oxygen sensors -- two upstream sensors called heated oxygen sensors and two downstream sensors called catalyst monitor sensors. These sensors monitor the SUV's emissions, so replacing a failed sensor is important to the health of the environment.

Instructions

Heated Oxygen Sensor Replacement

1

Raise the front of the Explorer, using a floor jack, and position jack stands under the SUV's frame rails. Lower the Explorer onto the jack stands.

2

Crawl beneath the vehicle and locate the two catalytic converters -- the two muffler-like exhaust components near the middle of the SUV. Look on the exhaust pipe in front of each catalytic converter and locate the heated oxygen sensor screwed into each exhaust pipe.

3

Trace the heated oxygen sensor's wiring upward until you reach where the sensor's wiring harness connects to the Explorer's wiring harness. Press the locking button and pull the sensor's harness from the vehicle's harness.

4

Remove the heated oxygen sensor, using a ratchet and oxygen sensor socket. Hand-thread a new oxygen sensor into the exhaust pipe and tighten it to 30 foot-pounds, using a torque wrench and oxygen sensor socket. Plug the oxygen sensor's wiring harness into the Explorer's wiring harness.

5

Repeat Steps 3 and 4 for the other heated oxygen sensor, if needed.

6

Raise the SUV off the jack stands, using a floor jack, and remove the jack stands. Lower the truck to the ground.

Catalyst Monitor Sensors

7

Raise the front of the Explorer, using a floor jack, and position jack stands under the SUV's frame rails. Lower the Explorer onto the jack stands.

8

Crawl beneath the vehicle and locate the two catalytic converters -- the two muffler-like exhaust components near the middle of the SUV. Look on the exhaust pipe to the rear of each catalytic converter and locate the catalyst monitor sensor screwed into each exhaust pipe.

9

Follow the heated oxygen sensor's wiring upward until you find where the sensor's wiring harness connects to the vehicle's wiring harness. Press the locking button and pull the sensor's wiring harness from the Explorer's wiring harness.

10

Remove the catalyst monitor sensor, using a ratchet and oxygen sensor socket. Hand-tighten a new catalyst monitor sensor into the exhaust pipe behind the catalytic convertor, and tighten it to 30 foot-pounds with a torque wrench and oxygen sensor socket. Plug the catalyst monitor sensor's wiring harness into the Explorer's wiring harness.

11

Repeat Steps 3 and 4 for the other catalyst monitor sensor, if needed.

12

Raise the SUV off the jack stands, using a floor jack, and pull the stands from under it. Lower the Explorer Sport Trac to the ground.