The P20F7 Code is concerned with the car engine and it is a short description of the problem. The P20F7 OBD2 reports a sensor fault, spare of the sensor is unlikely to resolution the underlying problem. The fault is most likely to be prompted by the systems that the sensor is monitoring, but might even be caused by the cabling to the sensor itself. Headlight bulbs and Indicator need steady care for them to keep functioning properly. Also the car paint ought to be in good condition because that reduces the probabilities of corruption taking over the body of your car.