The gist of the P20AD Code is necessary for solving the engine from the car engine and you have to get the genuine meaning of the P20B2 code of the engine from the car according to the brand. You will get the general meaning online but it is not helpful. The dictionary meaning of the code P20AD does not gives much information what is correct. So, read the manual of the car or get information of the code what manufacturer set as the model number of the car. Do not try to solve the car engines if you are sure about the problem. You cannot resolution the problem from the car engine and you may assignment more problem in the car engine.