1983-87 MODELS WITH ECM
See Figure 1
The oxygen sensor is a spark plug-shaped device that is screwed into the exhaust manifold on V8s and into the exhaust pipe on inline sixes. It monitors the oxygen content of the exhaust gases and sends as voltage signal to the Electronic Control Module (ECM). The ECM monitors this voltage and, depending on the value of the received signal, issues a command to the mixture control solenoid on the carburetor to adjust for rich or lean conditions.
The proper operation of the oxygen sensor depends upon four basic conditions:
- Good electrical connections-since the sensor generates low currents, good clean electrical connections at the sensor are a must.
- Outside air supply-air must circulate to the internal portion of the sensor. When servicing the sensor, do not restrict the air passages.
- Proper operating temperatures-The ECM will not recognize the sensor signals until the sensor reaches approximately 600ºF.
- Non-leaded fuel-the use of leaded gasoline will damage the sensor very quickly.
Oxygen sensors are extremely sensitive to silicone. Exposure to silicone will contaminate and destroy the oxygen sensor. Be careful not to use silicone sealers or lubricants in any area such as the intake or exhaust manifolds to prevent contamination. A white colored element or tip is an indication that the oxygen sensor has been contaminated with silicone.
REMOVAL & INSTALLATION
- Disconnect the electrical connector and any attaching hardware.
- Remove the sensor.
- Coat the threads of the sensor with a GM anti-seize compound 5613695 or equivalent, before installation. New sensors are pre-coated with this compound.