The good news, it is not the throttle body sensor. The bad news, the problem seems to be intermittent, and the mechanic could not replicate it. Judging only by the error codes (Apparently, there were several) they think the problem is either the MAP sensor or the computer itself. They can't say for sure until they can examine it when the problem is happening, or immediately after. For now, they sent the car back and told me to drive on as normal (no charge for the visit)