Odd one for you folks...
Sometimes when I back down my driveway in neutral with clutch engaged or with the clutch to the floor, the engine will start revving to about 1500 then dropping back to idle like vroom vroom vroom... but it stops once I start to do my thing.

Mind you, my foot is NOT on the gas, it is defintely on the brake or away from all pedals.

My mat is also not on my pedals.

 

yeah it will do that, usually when the engines been sitting in a cold garage or when you get off the freeway and the car had been at the same RPM for awhile, its natural. i believe its a problem with the way the computer interprets air intake, it has a hard time when the temperature changes rapidly too, like here in Minnesota when one day its 80 and the next its 30 degrees outside, i always get an engine light when the temp changes quickly in a day.

 

Ive seen my tach move a little on its own, as long as i dont go zipping down the street out of control im not gunna worry about it.

 

Welcome to owning a fly by wire car...