The 2002 Toyota Tundra has four oxygen sensors, one on each side of the engine, installed in the exhaust manifold, and one behind each catalytic converter. Sometimes the ones in the exhaust manifold can be difficult to remove because they rust in place, but some rust penetrant solves that. All four sensors can be replaced if need be for hundreds less than the dealer charges for one replacement. A code scanner is needed to determine which one is at fault.
Instructions
- 1
Plug the code scanner plug into the onboard diagnostics (OBD) port, located just above and slightly to the left of the gas pedal. Toyota has even installed a light to illuminate it. Turn the ignition key to the run position without starting the engine.
2Press the Read key on the scanner. Write down the codes displayed on the scanner and turn off the ignition key. Cross-reference these codes with the code sheet that accompanies the scanner for an explanation of the codes. The sensor at fault will be revealed.
3Soak the oxygen sensor to be replaced with rust-penetrating chemical. Allow it to set for a half an hour and soak it again. Allow an hour for the rust-penetrating chemical to work so you can remove the sensor with no problems.
4Replace the oxygen sensor in the exhaust manifold using the special oxygen sensor socket. Disconnect the electrical connector at the main harness by following the wires from the sensor to the connector about a foot away. Turn the sensor counterclockwise with the socket to remove it.
5Coat the threads of the new sensor with anti-seize compound before installation. Install the sensor and turn it clockwise to thread it into the manifold. Tighten it to 32 foot-pounds with a torque wrench and oxygen sensor socket.
6Connect the electrical connector to the harness. Replace the rear oxygen sensor by disconnecting the electrical connector. Remove the two 12 mm bolts securing it to the exhaust. Lift the sensor out along with the underlying gasket.
7Replace the gasket with the new one that accompanies the new sensor. Install the sensor and tighten the two bolts to 16 foot-pounds of torque with a torque wrench and socket. This is equivalent to a slight snugging of the bolts. Plug in the electrical connector.
8Turn the ignition key to the On position. Depress the Erase key, and the scanner will erase the code from the computers memory and turn the check engine light off. Disconnect the scanner and turn off the ignition key.
