See Figures 1, 2 and 3
An oxygen sensor is used on all models. The sensor protrudes into the exhaust stream and monitors the oxygen content of the exhaust gases. The difference between the oxygen content of the exhaust gases and that of the outside air generates a voltage signal to the ECM. The ECM monitors this voltage and, depending upon the value of the signal received, issues a command to adjust for a rich or a lean condition.
No attempt should ever be made to measure the voltage output of the sensor. The current drain of any conventional voltmeter would be such that it would permanently damage the sensor.
REMOVAL & INSTALLATION
The sensor may be difficult to remove when the engine temperature is below 120°F (48°C). Excessive removal force may damage the threads in the exhaust manifold or pipe; follow the removal procedure carefully.
- Disconnect the negative battery cable.
- Locate the oxygen sensor. It protrudes from the exhaust manifold (it looks somewhat like a spark plug).
- Disconnect the electrical wiring from the oxygen sensor harness.
- Spray a commercial solvent onto the sensor threads and allow it to soak in for at least five minutes.
- Carefully remove the sensor with a special oxygen sensor socket.
- First coat the new sensor's threads with GM anti-seize compound No. 5613695 or the equivalent. This is not a conventional anti-seize paste. The use of a regular compound may electrically insulate the sensor, rendering it inoperative. You must coat the threads with an electrically conductive anti-seize compound. Installation torque is 30 ft. lbs. (41 Nm). Do not overtighten.
- Reconnect the electrical wiring. Be careful not to damage the electrical pigtail. Check the sensor boot for proper fit and installation.
- Reconnect the negative battery cable.