Tahoe 2WD V8-6.0L Hybrid (2008)
Oxygen Sensor: Service Precautions
Heated Oxygen and Oxygen Sensor Notice
Heated Oxygen and Oxygen Sensor Notice
Notice: Do not remove the 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 free 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 if 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 are not 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.
Silicon Contamination of Heated Oxygen Sensors Notice
Silicon Contamination of Heated Oxygen Sensors Notice
Notice: Contamination of the oxygen sensor can result from the use of an inappropriate RTV sealant (not oxygen sensor safe) or excessive engine
coolant or oil consumption. Remove the HO2S and visually inspect the portion of the sensor exposed to the exhaust stream in order to check for
contamination. If contaminated, the portion of the sensor exposed to the exhaust stream will have a white powdery coating. Silicon contamination causes
a high but false HO2S signal voltage (rich exhaust indication). The control module will then reduce the amount of fuel delivered to the engine, causing a
severe driveability problem. Eliminate the source of contamination before replacing the oxygen sensor.
Excessive Force and Oxygen Sensor Notice
Excessive Force and Oxygen Sensor Notice
Notice: The oxygen sensor may be difficult to remove when the engine temperature is below 48°C (120°F). Excessive force may damage threads in the
exhaust manifold or the exhaust pipe.
Heated Oxygen Sensor Resistance Learn Reset Notice
Heated Oxygen Sensor Resistance Learn Reset Notice
Notice: When replacing the HO2S perform the following:
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A code clear with a scan tool, regardless of whether or not a DTC is set
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HO2S heater resistance learn reset with a scan tool, where available
Perform the above in order to reset the HO2S resistance learned value and avoid possible HO2S failure.
Oxygen Sensor Notice
Oxygen Sensor Notice
