why is my car emitting black smoke from the exhaust

yes my engine light is on. I live in the Caribbean on the island of St.maarten. there is no dealership for Mercedes benz. so I fix any problem myself. could it be a fuel regulator problem or clogged fuel injectors?. If I know what the problem is, i'm sure I can fix it. HELP NEEDED. besides, dealers, generally speaking charge super expensive in most cases for minor issues.

The problem is: we can't diagnose your problem over the Internet. It takes hands on testing using test equipment and shop manuals. The assistance I and others provide on here most often is advisory only, with basic information and guidance. No one can really give you guidance at the level you are hoping for from behind a computer. Only from under the hood. I respect that your location provides a challenge, but technicians study and train very hard to be very good at performing diagnosis and repairs, and invest significant financial resources in tooling and equipment. This is why they can diagnose and repair cars, and why it costs money to do it. I apologize that we cannot really give you further guidance, other than giving you a high level "guess" as to what could be happening with your car. PS, I didn't specify dealership. I said local trained technician familiar with Mercedes-Benz vehicles...