CAUTION
Perform this work only after the exhaust system has cooled enough to avoid burns.
It is more common to remove the oxygen sensor for protection or access during
other repairs than to replace it because of failure. Once the sensor is removed,
it must be protected from impact and/or chemical contact. Never attempt to clean
the tip with solvent and never allow the tip to contact grease, oil or other
chemicals. The zirconia element in the tip will be polluted and the sensor will
function poorly, if at all.
- Locate the oxygen sensor. On 4-cylinder engines, it will be located in the
exhaust manifold, usually mounted either underneath or from the side. The
6-cylinder engines have the oxygen sensor mounted in the exhaust pipe, just
beyond the Y where the left and right pipes connect into one.
- Follow the wiring from the sensor to the first connector and disconnect
it. Do not attempt to disconnect the wiring at the sensor.
- Particularly on non-turbocharged, 4-cylinder engines, the sensor may be
obstructed by heat shields on the exhaust manifold. Remove them as necessary.
- Install the proper size wrench on the flats of the sensor. Place the socket
on the sensor and use a box wrench to turn the socket.
- Keeping the wrench (or socket) square to the sensor while removing it. Do
not allow the wrench to become crooked or to come off the flats. Remember
that the sensor has been exposed to extreme temperature and corrosive exhaust
gasses. It may be difficult to remove.
- Once the sensor is removed, place it in a clean, protected location. For
reinstallation, the threads of the sensor may be lightly coated with an anti–seize
compound but extreme care must be taken to protect the tip and shield area
of the sensor from even the slightest contamination.
- Handle the oxygen sensor carefully, protecting it from impact, and install
it in place. Start the threads by hand and hand-tighten it as far as possible.
- Finish by tightening the sensor to 33 ft. lbs. (45 Nm).
- Install the heat shields if any were removed. Tighten the bolts to 12 ft.
lbs. (16 Nm).
- Connect the sensor wiring to the harness connector. Make certain the wiring
is correctly run and out of the way of hot or moving components.
