Mercedes SL Reduced Engine Power Issue

That sounds familiar! I've got an SL too, and something similar happened not too long ago. Did you check the connections to the ECU to ensure they are tight and clean? What error codes are you pulling up?

I'll double-check the connections. I don't have the error codes right now. When you had a similar issue, was it also the engine control unit on your SL? Did a system reset solve your problem, or did you have to do something else?

It was the ECU for me too, or at least, that's what the workshop said. I didn't mess with the system reset myself. If you're getting ECU errors, it's probably worth having a pro take a look. It could be a dodgy relay as you suspect, but best to confirm before replacing parts. It could save you cash and headaches!

Sounds like a workshop visit is the way to go. It was a defective main relay. The ECU was throwing codes because of it. Got it sorted for 120€. Thanks!