Your 1996 Mercedes C220 has the check engine light on What should you do?

Theres a number of things you can do. You can buy the reading tool or if you dont feel up to it you can just take it down to your local auto parts store(Autozone, O'reillys or Pep Boys, etc... you get the idea) they should be able to point out the fault. Just keep in mind that if you're trying to get it to pass emitions, the car needs to do at least 150 miles in order to for computer to reset and truely show no fault. Hope this helps. Best of luck to you!