The engine P0991 Code has various meanings but you will accept the right meaning. The right meaning of the code is provided by the car manufacturer only. Here, the problem is found in the car engine’s powertrain and the powertrain of the car engine is easy to fix. Do not allow false meaning of the code or do not allow any meaning of the code what has no any relation with the car or the car engine. You must love to fix the car engine properly. Due to use of the false meaning of the code, new problems can be started in the car engine.