Larry’s description too says “clogs the pores” and “basically destroys the sensor”, but if in that description he means the sensor is destroyed by the pores being clogged then my method “MAY” work.

I’m using the CRC electronic parts cleaner like a person would OXYCREAM for their face except for the sensor element by soaking it in there hoping to unclog the pores. I will post back and let you know what happens. I just wish I could get myself to buy a scan tool $$$. lol

Here’s a clip from Larry Carley’s website (www.aa1car.com) on how an oxygen sensor works.

“The O2 sensor is a miniature generator and produces
its own voltage when it gets hot. Inside the vented cover on
the end of the sensor that screws into the exhaust manifold is
a zirconium ceramic bulb. The bulb is coated on the outside
with a porous layer of platinum.
Inside the bulb are two strips of platinum that serve as
electrodes or contacts. The outside of the bulb is exposed to
the hot gases in the exhaust while the inside of the bulb is
vented internally through the sensor body to the outside
atmosphere.”

So any contamination from coolant or RTV silicon, excessive oil, soot, etc, clogs the pores and basically destroys the sensor.

Feel free to clean it—I’ve never seen it work. But if it does, more power to you. I’m betting that yours is toast. The only upside to cleaning is that it will be easier to remove when you have to install a new one.

If there has been no backfire or physical damage/trauma to the sensor then why can’t you simply clean the sensor element with CRC electronics parts cleaner or MAF cleaner?

From your photos my O2 sensor on the front upstream side had a coolant experience which I know I had a blown head gasket in the previous engine. Since then I’ve gotten horrible 9-11mpg with the new engine though I have also determined my MAS was dirty and cleaned it as well as a likely faulty radiator cap (lack of proper coolant level in engine) and low speed cooling fan resistor which likely all are contributing to the bad MPG.

There was also a misfire condition in the old engine causing fuel to go down the exhaust as well and the top of this sensor at the wire’s connection point was caked/covered with sludge/debris.

I have used the CRC electronic parts cleaner to clean my O2′s and put them all back in. I haven’t run the vehicle on the road yet pending exhaust work, but I have started it for 5 minutes twice and got no CEL. I have the 4 wire heated sensors too. My method of cleaning involved soaking the sensor element in the CRC electronic parts cleaner in a cap for the sensor for 2 hours, spray clean again afterwards, and let dry.

Mainly I’d like to know why/how a sensor “wears out” beyond physical damage as it seems the proper terminology would be “O2 sensors become dirty and plugged over time causing their performance to degrade”. I’m not attacking you by any means, but I’ve looked into this in depth on the web and it doesn’t make sense to me how the sensor becomes useless if its not physically damaged and can be cleaned for reuse. Comments?

searcherrr – on automotiveforums.com