Why does the engine warning light remain on

The engine light is telling you theres something wrong with your car and that you need to give it some attention . You can start by getting a OBDll reader and getting the code to tell you just what you need to fix. Once you have the code and have fixed the problem you can delete the code and the light will be out

You do not give us a lot to go on. I suggest that you get the OBD scanned at places like Autozone or others and see what code it returns. there are hundreds of reasons why the light could be on.

Replace the engine if it's bad