It might be a rusted gasoline filler pipe.  Clean the rust off the pipe and
the gas cap gasket.  Apply a layer of thick grease to both surfaces and see
if that fixes it.       is@yahoo.com> wrote in message
news:1182523788.051467.19150@i38g2000prf.googlegroups.com...

Are you sure is O2 sensor?  or are you talking about CO2?

I hope your motor oil is not flooding above the High level, some oil could
get into the combustion chamber and that oil could get burned going through
the exhausted pipe where the sensor is watching for poor quality gas, that
could very well be the cause of your CO2 sensor to go off, when this
happened you will see "Check Engine" light coming up.

Sensor shouldn't go bad so quickly.

If it is flooded, then pump off your oil through the same hole where you
check your oil.  Go get a Wal-mart a hand pump to suck off some of your
motor oil.  Problem should go away.

Another test you should do, you should switch the pump station, to see if
the problem will go away, if it did then maybe the other pump sold poor
quality gasoline.

Good luck.