Do Not Clog O2 Sensor Air Vents with Sealant, Anti-Seize Paste or Dielectric Grease

[Moses Ludel]

There are areas where you should not use dielectric grease, RTV sealant or anti-seize paste.   One worth mentioning is certain oxygen sensors (O2 devices).  Some O2 sensors draw ambient air where the wires enter the sensor housing.  Sometimes There is a port like the vent opening shown in the illustration below.  These O2 sensors depend on ambient air for a baseline voltage reading.  Deviations from that point trigger the PCM/ECM/ECU to adjust or "trim" fuel mixtures. 

Be certain that you know where the O2 sensor's ambient air port or ambient air entry point is located.  If at the connector, do not put dielectric grease, RTV sealant or anti-seize paste where it could block this air source.  Know the type of O2 sensor used and how or where it draws ambient air.

This generic O2 sensor image shows the vent to atmosphere.  Air is sometimes sourced through a padding where the wires enter the top of the sensor.   Do not plug this port or the area where the wires enter the top of the sensor:

For more information on O2 sensors, Walker Products has a training guide on O2 sensors that is helpful.  The guide explains the functions, troubleshooting and service needs of O2 sensors.  Proper use of anti-seize on threads of new sensors is illustrated:

https://www.walkerproducts.com/wp-content/uploads/2020/06/Oxygen-Sensor-O2-Training-Guide.pdf

Moses