Focus slowing to a stop

The car is going into 'limp home' mode, which suggests there is something amiss with the electronics of the engine management system, possibly the ECU or a sensor supplying it with information. It needs to be sorted out by the dealer; it's not good enough to tell you to keep bringing it back when it happens. By doing that they're hoping to eventually stumble on the cause of the problem rather than investigate the cause and find a solution. If you can't get any sense out of the dealer go directly to Ford's customer assistance service on 13 3673.