Very often a CEL is emissions related. Check your gas cap and make sure it's on tight. Caps sometimes go bad, so you might want to get it tested or buy a new one if it's inexpensive. To find out what the CEL issue is, you'll need the fault codes. Stop into an auto parts store and buy an inexpensive Bluetooth OBD2 reader and install an app on your phone (I use Torque; not sure if it's available in Europe) to read the fault codes and clear them. Sometimes clearing the code is all you need to do, if it's an intermittent emissions issue and doesn't recur. You can use the internet to decipher the fault codes.

 

I'm happy to say that the Check Engine light is now off. I guess the car found out I was more stubborn than it was :-). I'll have it read when home, but since it's gone now and the car drives fine, I'll motor on...

The light came on when doing 150-180 km/h. Have I heard once that a low backpressure exhaust like mine can trick a Check Engine light?

 

Glad your issue is solved, if only temporarily, enjoy your trip.