Kind of hard to understand what you mean, but what I think you are saying is the when you flog it in neutral, and let the revs go back down, they dont immediately drop but stay at 2k for a bit and then drop??
Mine does the same thing too if that is exactly what you are trying to describe. I believe it has to do with the safety features of the ecu so you don't leave extra fuel in the cylinders from reving it constantly. That and the stock flywheel is REALLY heavy. From factory I believe it is almost 25lbs? So a little 4 cylinder is going to have a tough time spinning it first off, but also controlling it to drop. But its good for gas mileage.