The engine P20D8 OBD2 may also be activated by liabilities earlier down the line. Such as, a dirty MAF sensor might be producing the car to overcorrect in its fuel-trim adjustments. So, the oxygen sensors are likely to account the fuel mixture problems. The meaning of the code P is Powertrain Code – Problem is related engine, transmission and emissions systems. 2 is MFG – Manufacturer Specific. 0 is Transmission. D for BBV Sensor Circuit Low Voltage and 8 for Park/Neutral Position (PNP) Switch Circuit Engine Torque Signal Circuit. Do not use this meaning for solving the car engine problem.