The engine P0474 Code has started due to some other problems and those are exhaust pressure sensor failure, powertrain Control Module (PCM) failure and wiring issue. You need to test the car engine and symptoms to know the real cause of the car engine problem. The car engine is easy to fix if you know the real meaning of the code. You should be expert for solving the car engine problem and if you do not know the process of solving the car engine, you should not try to fix the car engine. You can hand over the car to automobile engineer to fix the car engine.