The engine P0691 Code is important thing but the real meaning of the code is more important than the code appears on the engine code reader. The engine code is supporting content only but if you have no right meaning of the code, it is not possible to solve the car engine’s problem fast. The engine should be fixed by an expert automobile engineer with the proper information. If you have expertise, you should not try to fix the car engine. You may get new problems in the car engine and that maybe more difficult to solve for costing and level of difficulties.