O2 sensor?

[MustangChris]

What does an o2 sensor with white on it mean? I assume o2s kind of have the same quality of spark plugs where different deposits/colors/textures mean something.... mine looked covered in powder sugar (that wouldnt rub off.)

for the record:
4 o2 sensors
2 cats

2 pre cat sensors
2 post cat sensors

used sea foam twice in the lifetime of these o2s, which has been about a year now.

thanks! :-D

 

[brad94GT]

the main part of the o2 sensor is on the inside

 

[CC'S95GT]

white means lean but not necessarily bad