BigTex
Member
- Joined
- September 8, 2011
- Messages
- 15
- Reaction score
- 4
- Location
- Keller, Texas
- City, State
- Keller, Texas
- Year, Model & Trim Level
- 2002 Explorer XLS
After replacing many O2 & HO2S sensors in my time, I didn't bother to learn how they work and the external environmental factors that make them fail. That is until I came across this very informative article explaining why I'm replacing the same HO2S for the third time in a few years. My problem turned out to be a small oil leak from a rear valve cover dripping down the O2 wire, causing the ambient air source to become blocked on the sensor with all the caked on oily grime. I've since learned that oil and grease contamination is the cause of many Upstream O2 & HO2S sensors failures. Time to fix that little oil leak!
Understanding O2 sensors
I hope this helps someone. My Explorer has four O2 sensors; right & left cat, upstream & downstream. And the only one that's failed is the one covered in oil. Go figure...
Understanding O2 sensors
I hope this helps someone. My Explorer has four O2 sensors; right & left cat, upstream & downstream. And the only one that's failed is the one covered in oil. Go figure...
