Cutlass Supreme V6-191 3.1L VIN M SFI (1997)
Oxygen Sensor: Service and Repair
Notice: The Heated Oxygen Sensor (HO2S) and the Oxygen Sensor use a permanently attached pigtail and connector. Do not remove this pigtail from
the Heated Oxygen Sensor. Damage or the removal of the pigtail or the connector could affect the proper operation of the sensor.
Take care when handling the HO2S. Keep the in-line electrical connector and the louvered end free of grease, dirt, or other contaminants. Also avoid
using cleaning solvents of any type. Do not drop or roughly handle the HO2S.
If the heated oxygen sensor pigtail wiring, connector or terminal is damaged, the entire oxygen sensor assembly must be replaced. Do Not attempt to
repair the wiring, connector or terminals. In order for the sensor to function properly, it must have provided to it a clean air reference.
This clean air reference is obtained by way of the oxygen sensor signal and heater wires. Any attempt to repair the wires, connectors, or terminals could
result in the obstruction of the air reference and degraded sensor performance.
The following guidelines should be used when servicing the heated oxygen sensor:
^
Do Not apply contact cleaner or other materials to the sensor or vehicle harness connectors. These materials may get into the sensor causing poor
performance.
^
The sensor pigtail and harness wires must not be damaged in such a way that the wires inside are exposed. This could provide a path for foreign
materials to enter the sensor and cause performance problems.
^
Neither the sensor or vehicle lead wires should be bent sharply or kinked. Sharp bends, kinks, etc., could block the reference air path through the
lead wire.
^
Do Not remove or defeat the oxygen sensor ground wire (where applicable). Vehicles that utilize the ground wired sensor may rely on this ground
as the only ground contact to the sensor. Removal of the ground wire will cause poor engine performance.
^
To prevent damage due to water intrusion. be sure that the peripheral seal remains intact on the vehicle harness connector. The engine harness may
be repaired using Packard's Crimp and Splice Seals Terminal Repair Kit. Under no circumstances should repairs be soldered since this could result
in the air reference being obstructed.
Removal Procedure
CAUTION: The heated oxygen sensor may be difficult to remove when engine temperature is below 48°C (120°F). Excessive force may damage
threads in exhaust manifold or exhaust pipe.
1. If HO2S 2 is being replaced, raise the vehicle.
2. Disconnect the electrical connector.
Important: A special anti-seize compound is used on the heated oxygen sensor threads. The compound consists of graphite suspended in fluid and
glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service sensors will already
have the compound applied to the threads. If a sensor is removed from an engine and if for any reason is to be reinstalled, the threads must have
anti-seize compound applied before reinstallation.
3. Carefully back out the heated oxygen sensor.
Installation Procedure
1. Coat the threads of heated oxygen sensor/catalyst monitor with anti-seize compound P/N 5613695, or equivalent if necessary.
2. Install the Heated Oxygen Sensor.
Tighten
^
H02S 1 (Pre-catalytic converter) to 42 +/-4 Nm (31 lb. ft).
^
H02S 2 (Post-catalytic converter) to 42 +/-4 Nm (31 lb. ft).
