C 3500 Truck 2WD V8-454 7.4L VIN J SFI (1999)
Oxygen Sensor: Service and Repair
REMOVAL PROCEDURE
NOTE: Do not remove this pigtail from either the heated oxygen sensor (HO2S) or the oxygen sensor (O2S). Removing the pigtail or the connector
will affect sensor operation.
Handle the oxygen sensor carefully. Do not drop the HO2S. Keep the in-line electrical connector and the louvered end tree of grease, dirt, or other
contaminants. Do not use cleaning solvents of any type.
Do not repair the wiring, connector or terminals. Replace the oxygen sensor it the pigtail wiring, connector, or terminal is damaged.
This external 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:
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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.
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Do not damage the sensor pigtail and harness wires 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.
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Ensure the sensor or vehicle lead wires should not be bent sharply or kinked. Sharp bends or kinks could block the reference air path through
the lead wire.
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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.
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Ensure that the peripheral seal remains intact on the vehicle harness connector in order to prevent damage due to water intrusion. 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.
The Heated Oxygen Sensor (HO2S) may be difficult to remove when the engine temperature is below 48°C (120°F). Excessive force may damage the
threads in the exhaust manifold or the exhaust pipe.
1. Disconnect the negative battery cable.
CAUTION: Refer to Battery Disconnect Caution in Cautions and Notices.
2. Determine the location of the HO2S to be removed.
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle.
4. Remove the HO2S electrical connector by releasing the locking tab. The electrical connector may typically have either a 1x4 or 2x2 configuration.
