Engine light comes on no matter how much we spend to fix it. Is it a Recall?

What is your question?

Engine light has been reset, stays off for maybe a few days comes back on. Dealership says its "this", fixes it & the light come back on. This has happened too many times. They always say oh we figured it. This has been going on for years. The engine seems fine but they find a way to charge us big bucks to fix it.?. Never fixed. PLEASE HELP US!!!!

What makes this problem better or worse?

Nothing at all it just comes on, stays on?

How long has your 1999 Mercedes-Benz SL600 had this problem?

since we bought it 6 years ago.