2010 Cadillac Escalade ESV Oxygen Sensor

The procedure is to raise and support the vehicle, remove the connector position assurance (CPA) retainer, disconnect the engine wiring harness electrical connector from the HO2S, remove the HO2S electrical connector clip from the fuel line clip, remove the CPA retainer, remove the engine wiring harness electrical connector clip from the fuel line clip, and then remove the HO2S.

The procedure is to raise and support the vehicle, remove the connector position assurance (CPA) retainer, disconnect the HO2S electrical connector from the engine wiring harness electrical connector, and then remove the HO2S.

The proper way is to install the HO2S and tighten it to 42 Nm (31 lb-ft), connect the HO2S electrical connector to the engine wiring harness electrical connector, and then install the CPA retainer.

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 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.

You should not remove the pigtail from either the heated oxygen sensor (HO2S) or the oxygen sensor (O2S), handle the oxygen sensor carefully, do not drop the HO2S, not use cleaning solvents of any type.