Has anyone else experienced an intermittent lack of turbo boost, where the 2011 9-4X Aero 2.8 goes into limp mode? It seems to only happen during warm summer days and going up hills. It didn't happen at all over the fall and winter months. Sometimes the engine light will come on and sometimes it will not. The engine code is p0299, turbo underboost. The turbo will reset and provide normal boost after the car is restarted.