This sensor has been causing a CEL for me sporadically. It goes on and off while driving and usually turns on or off when I accelerate or lightly rev the engine. Some symptoms are Back fires, acceleration hesitations.

Does this CEL code 11 typically mean the sensor is bad? Or is it more often the connector or harness failing? I recently removed this sensor the last time I had my UIM off, and tested it. I felt like it was in working condition.

 

Anything is possible, but the overwhelming likelyhood is that the sensor is bad. They don't cost all that much.
Mine failed and I used the occasion to re-locate the faster reacting version just upstream of the throttlebody and away from alot of the heatsoak that it got under the UIM. Just solder a little extra wire for the 2-pin connector. Took all of 30 minutes.