Happened to me when I first got mine. Was pushing the car hard and that would happen. Turned it off and on and was good again. Took it to the dealer but never told them about that as I thought that was typical from pushing too hard. They replaced all of my coils and it hasn't happened again.
Then, later, after I added methanol and a new charged pipe, the nylon elbow that came with the kit kept sliding off the charge pipe and making a loud "pop" noise resulting in the same "reduced power" warning (poor install on my part).
The good news is the car still runs pretty good and the system "self protects" from engine damage.
I'm sure you have some codes thrown so get those codes read and go from there.
Hopefully it's coil related and not injectors. Those bad boys are expensive and need to be coded in. Dealership did mine later due to a recall or something.
Not sure if VANOS solenoids could cause that either (engine timing and oil pressure related) but those look easy to fix as well.
Last edited by sptt144; 09-02-2014 at 10:19 PM.