The engine P242F Code is a meaningful code and do not use any meaning of the code for solving the car engine problem. You must use right meaning of the code and then it becomes easier to solve the engine problem. The engine P242F OBD2 may also be generated by error earlier down the line. Such as, a dirty MAF sensor might be producing the car to overreact in its fuel-trim adjustments. So, oxygen sensors are likely to report fuel combination problems. Many symptoms are available what you need test to identify the real cause of the car engine problem.