Yeah, tell it to knock it off or your gonna trade her in.
It almost sounds like an intermitten ECU problem. Does it store any codes at all?
I once had a Vette with a similar problem, and it was actually due from an engine ground being in the wrong place (believe it or not). Have you had any work done on it right before you noticed this problem? If so, check the wiring harness around where whatever work was done and look for chafeed wires and loose connections. This is the most likely answer to Gremlins like this one.