Another thing I would do is check to make sure you have the correct springs installed in the Forge recirc valves.

 

I had a very similar issue with flash+exhaust and disconnecting the battery overnight solved the problem.

 

True...could be throttle body adaptation. If that's the case, try this:

Put the key into the "on" position so that all accessories are on but engine is not running. Leave driver's door open and go stand by the engine bay with decklid open. Listen carefully until you hear the throttle mechanism cycle and click. Then go to the front, cycle the ignition once and you should be good to go.

 

Bug Todd.

 

Interesting, was wondering if you could elaborate on what effect throttle body adaptation has and why it is needed.

My particular situation was same day installation of new flash, GT3 throttle body with Werks1 plenum, then driving from sea level to 6000 feet. Throttle response was terrible for a day or two at altitude until battery disconnected.

 

Because your throttle body is basically controlled by an electronic signal rather then a physical cable, performing a TB "adatation" resets the signal between the pedal and the throttle body, essentially. This makes sure that each percentage you depress the petal accurately transmits to the TB itself.

A dealer can do it with a PIWIS also, but this is sort of a primitive method that does work.