Fix It

Connect the code scanner cable end to the OBD port under the dash on the left side of the steering column. The scanner is needed to determine which sensor is defective. Turn the ignition key to the "Run" or "On" position.

Press the key marked "Read." The computer will display a five-digit code. Record this code. Cross-erence this code with the code sheet that accompanies the code scanner to identify the faulty sensor. Turn the key off.

Raise the vehicle with the floor jack and place jack stands under the frame. Lower the vehicle onto the jack stands. Disconnect the electrical connector from the faulty sensor. If the code indicated that the number 1 sensor is faulty, it will be the one between the engine and the converter. If the number 2 sensor is faulty, it will be the sensor on or behind the converter.

Remove the faulty sensor using the 7/8-inch wrench. Turn the sensor counterclockwise to remove it.

Install the new sensor and tighten with the wrench. Connect the electrical connector. Lower the vehicle with the floor jack.

Raise the rear lift gate of the Explorer with the vehicle parked, the engine off and the headlight switch in the "Off" position.

Locate the two (upper and lower) taillight assembly retaining screws on the painted section of the side rail on the left (drivers side) assembly. Remove the screws with the screwdriver.

Pull the assembly outward away from the rear of the Explorer. The wire harnesses of the rear lights are attached to the sockets of the bulbs, but the assembly can be pulled out far enough to obtain access to the bulbs.

Turn the socket of the taillight/brake light counter-clockwise about 1/3 of a turn. Pull the taillight/brake light out of the taillight assembly.

Pull the taillight/brake light straight out of its socket, and replace it with a 3157 automotive bulb.

Reinsert the taillight socket into the assembly by aligning the tabs on the socket to the notches in the assembly, then twist the socket clockwise until it locks into place.

Replace the taillight assembly to the body of the Explorer, then replace and tighten the retaining screws.

Idle the vehicle for about 15 minutes until the engine is warm.

Park the vehicle and set the parking brake. Let the vehicle remain running.

Lift the hood on you Explorer and locate the transmission filler tube and dipstick. It is generally located on the drivers side of the engine in the rear. It will be labeled with the word "Transmission."

Pull out the dip stick and wipe it with the paper towel. Look at the lines on the dipstick to find "Add" and "Full Hot." Replace the dipstick into the tube and pull out again to check the level. A low transmission level can cause major problems. If the fluid is full and it smells burnt, then your transmission could need a major rebuild or replacement.

Turn off the vehicle and let it cool down.

Slide under the vehicle with the flashlight and find the transmission. You will know the transmission because you will see the dipstick tube attached to it. Shine your flashlight all around the transmission and look for any wire connections that have become detached. You can also check to see if you have any major leaks.

Raise the front end of the Explorer Sport Trac by driving it up onto car ramps. Apply the parking brake and place a wheel chock behind one of the rear tires.

Put on the safety glasses and gather the tools, replacement sensor and creeper if you have one. Crawl under the front of the Explorer Sport Trac.

Locate the sensor to be replaced. These sensors are screwed into the exhaust pipes and components and wired to wire harnesses that communicate to the computer system of the Sport Trac. The information of which sensor to replace should have already been obtained. Follow the exhaust piping from the engine manifold back until you have located the correct sensor.

Locate the sensor wire outlet plug. Some of the sensors on the Sport Tracs have a tricky plug to get at. Remove the plastic plug clip from the frame of the Sport Trac by prying it out with the screwdriver, but be careful not to damage the wire harness side of the outlet. Unplug the oxygen sensor wire from the wire harness.

Use the ratchet and socket to remove the sensor. Place the sensor wire into the slot on the side of the socket.

Screw in the new oxygen sensor and tighten. Be careful not to over-tighten or you could damage the threads to the new sensor.

Plug the oxygen sensor wire into the wire harness and fasten it back to the frame if you removed it. Gather the tools and creeper and crawl out from under the Sport Trac. Remove the wheel chock and back the Sport Trac off of the ramps.