2008 Ford Focus electrical system problems

On numerous occasions, usually at speeds around 67 MPH, the engine looses power and goes to idle. It will not accelerate, but idles at 1100 rpms. The fix it light turns on. Once pulled over, I turn off the engine, then restart. It runs roughly for a moment the appears to run normally and the fix it light goes out. I have taken it to the dealer, but they will not drive it long enough to duplicate the event - usually happens every few hundred miles.

Vehicle suddenly lost power, only continuing to run at a rough idle. The vehicle would not allow any acceleration. The only possible response was to limp to the shoulder of the road. After turning off the ignition the vehicle was restarted and ran as normal for the rest of the trip. Four days later the same thing occurred. Upon taking the vehicle to the ford dealer and having them tell me to continue to drive the vehicle until it occurred again and then have it towed in, I convinced them to look further into it.