That is an O2 heater sensor failure indication - meaningless in the context of your complaint. If that was the code, I"m not sure it has ANYTHING to do with the symptom.
But since you are not sure, who knows....

I'm thinking MAF or Throttle body. We had a member in Georgia with a car that was acting up like this - a new throttle body fixed it. THe car would hardly idle, it would run and kind of keep up with traffic, but barely. Some days, it would run fine. This went on for at least three weeks. Finally, one of us changed her TB with a spare he had. FIXED.
Her TB was really insane, you'd turn the key to "ON" and the TB would sit there making noises constantly, it could not decide where to position the butterfly with the engine not running!