The car engine C1791 Code gives you information of the car engine problem and that is why, you need to seek the correct meaning of the code. By following the wrong meaning of the code, it is not possible to solve the car engine problem. Read the car engine manual to know the name of the car and know the car model. It is not necessary to use general meaning of the code. Do not drive the car with any type of car engine problem. You can read the automobile dictionary meaning of the car engine but do not follow that meaning for engine problem solution.