The car engine code B2451 is necessary item for solving the problem from car engine. You need to get the real meaning of the code and if you do not identify the real meaning of the code, you cannot solve the car engine problem. You should read the manual of the car engine or you may know the manufacturer name and model number for finding the real meaning of the code. You may read the general meaning of the code but it is not helpful very much for solving the car engine problem. Do not worry with problematic car, you can solve it easily.