i changed my O2 sensor today and it was covered in a light brown to white powder on it. is that an indication of me running lean??? i have and A/F gauge coming soon but if this is and indication of me running lean im gonna stop driving it at least till that gauge gets here...

 

Most all O2 sensors have a powder like you described when they are taken out. Unless there are other reasons why you think you are running lean, I would not be too worried about it.

 

if you have no idea when the last time your O2 sensor was replaced, is it worth replacing or should you not worry about it till its done..things that i keep hearing about that have problems and i dont know when the last time they were changed makes me really want to change them (thermo, O2, plugs, wires, fuel filter, pump)

 

i had no idea when everything had been done last when i bought my car so iv slowly been changin all of it. what comes stock on these cars the O2 sensor that i took out was a NGK not a mazda part?

 

The light brown stuff is normal.&nbsp What it is is all the gasoline additives the engine burns...



-Ted