nismosentra

Is it possible that smoke could form from the o2 sensor? The engine does not sound as it usually does. (deeper growl). I filled up the coolant to make sure nothing is wrong.

Nostrodomas

I have not head of the o2 sensor giving off any smoke. I dont really see how that could be posible, unless the sensor is on fire.
Maybe you can explain your problem a lil bit more. Where is the smoke comming out of? What color smoke is it? When does it smoke?

nismosentra

The dark milky smoke for a duration of 2-3 seconds seemed to have come directly from the oxygen sensor area. The engine was quite hot at the time, and possibly something (small debris?) fell on the hot metal surrounding the o2 sensor causing the illusion that the smoke was coming from the o2 sensor?

Nostrodomas

Maybe check the loom or wiring. See if its has melted, or fried. Thats the only thing I can think of.