The P20CF Code is found at the time of the car engine is tested by the car engine code reader. So, it is easy to identified that where the problem is. Now get the meaning of the code according to the manufacturer of your car. You may use general meaning of the code but that does not very helpful for solving the car engine problem. However, you should study the manufacturer meaning for solving the car engine. The engine code is available all manufacturer of the car. The same code is found in different manufacturer car but meaning of the code does not remain same.