OK, background-had the check engine light come on last week. Took it in and the dealer said it just needed some of the software modules updated. Well, that DID clear the code. However, on the way in to work this morning, it triggered again. Seems I can trigger it at will by accelerating from a standstill briskly (well, as briskly as you can in traffic) then lifting completely causing overrun. Soon as I lifted completely (second gear, iirc) the light popped on. Any clue as to what it could be so I can be sure they fix the right thing this time?