Silicon Contamination Of Heated Oxygen Sensors Notice

WARNING: This page does not describe the selected car, but rather 249 other vehicles, including the 2004 Saturn Vue, 2004 Saturn L300, 2004 Saturn Ion Red Line, 2004 Saturn Ion 3, and 2004 Saturn Ion 2. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: 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 & 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.