That failed to fix the Check Engine light problem.
I took it to a more local dealer later in February (I had been away at the time of the first repair) and they replaced an O2 sensor AND an Air Flow sensor on "good will" because of the fact that I was TOTALLY fed up AND that I had reported to customer service that they didn't seem to know what the hell they were doing.
Over this past weekend, the Check Engine light came on again and so I took it in to be looked at again. This time I was told it was an Oxygen sensor and that apparently the last time anything was replaced, it was ONE of the Air Flow sensors and ONE of the Oxygen sensors, although they are usually referred to the same. (WTF?!) The only difference being that there was about $100 price difference between the two sensors.
I called the other dealership back and their records were no help. All their records said was "oxygen sensor"...
So now I am looking at another $300 repair on a 2005 Prius.
I'm probably going to have it done but I am NOT happy about this.