Just started running into this problem about a month and a half ago. I was driving in a torrential downpour, CEL flipped on so I pulled off of the e-way and noticed the idle was a bit "lop sided" best I can say is it sounded kind of like it was "cammed." when I went to take off from a stop the motor hesitated a little bit for about 2 seconds then would take right off no problem. This would only happen probably once or twice in a half hour long drive, and more prominently when I would hot start the motor. Like if I went into a store and came back out a couple of minutes later.
The CEL pulled a code for an O2 sensor, although I accidentally threw the piece of paper with the code number on it away
Resetting the computer resolved this issue and I drove it for about a solid month before it came back again, I was in a rush, had a bunch of places to be so I reset the computer again and kept driving, but same symptoms; lop sided idle, hesitating at take off, etc.
Today, the CEL remains off and has for the past 400 miles since the last reset, but while cruising at about 30 mph, motor at about 1800 rpm it started to sputter and buck. Pushing the accelerator pedal down a little bit resolved this and it stopped again.
I have never had an O2 sensor fail on me, but given thats the code it gave me last time, would this be the correct symptoms for a failing O2 sensor?