I just had some work done on the engine (3.2 V6) - on the way home from the shop (picked it up after-hours, of course, so there was no one to check with), anytime the engine is over about 1900-2000RPM, the check engine comes on, flashing - when the engine drops down back under 1.9-2kRPM, it goes off again - I don't notice any performance/sound changes; other than the light, there's nothing going on - any ideas?

- Scott