The engine P2138 Code is found only form the car engine by the test of the car engine. That is why, you should check the car engine in the car engine repair center. You will get help from an automobile engineer and many necessary machines and tools are there. So, you must not take any step what will be wrong for your car engine. You do not try to check or solve the car engine in wrong way in your place. You should confirm that you have done all things correct for your car engine. When the car engine is ok take a test drive.