The engine P202F Code is a trouble code and this code explains about the car engine problem. It is called Reductant/Regeneration Supply Control Circuit Range/Performance. For the powertrain problem of the car engine, the engine problem has started. The solution of the car engine is necessary. Like the all other car engines, this engine method employs particularly advanced hydraulic lifters what is known as switching roller followers for the P202f code intake and finish valves. The lifters can be distorted by disengaging an inner locking pin. The locking pin is disengaged by means of solenoids to change oil pressure fed into the lifter.