When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I ran across this article on oxygen sensors I thought was interesting. I was suprised to read that even silicone gasket sealer on valve covers can cause a problem with an O2 sensor.
It’s possible, but very un-likely. The silicone would have to come loose, pass through a valve enter the combustion chamber, pass back out a valve and then land on the sensor. I doubt enough would survive long enough to damage the valve but then anything is possible.