Yep, when in question you can pop the hood and you will here a clicking sound. That is the evap solenoid pulsing to vent the gas tank vapors into the engine. Unplug it and the car will smooth out and things will go back to normal. It would be nice if there was a table for turn on time for this so it would not do this sitting at idle. With a stock cam its hardly noticable but with a larger cam it seems to show up more.