Skoda Roomster Diesel rough running

Rough running and a check engine light? Sounds like you're on the right track with the injectors. 'Drift compensation,' as you called it, is where the ECU (that's the car's computer) tries to even out the fuel delivery if one or more injectors aren't performing perfectly. So, if it's throwing an error and running rough, it's probably maxed out its ability to compensate. Have you noticed any change in fuel economy lately? Also, do you know which injector is causing the problem?

Fuel economy seems normal. How do I find out which injector is the problem? Is the reset procedure something I can do myself?

Okay, if the fuel economy is normal, that might point to a smaller issue with the injector, but it's still significant enough to cause problems. As for finding the faulty injector, that usually requires diagnostic software that can read live data from the engine. The 'reset procedure' you mention is also done through software. While there might be some DIY ways to check injectors, without the proper tools, you could do more harm than good. I would suggest taking it to a workshop.

Thanks for the help. I took it to a workshop, and you were right, an injector was faulty. They replaced it and performed the 'reset quantity drift compensation' procedure. The final bill was 515€. Runs like new now!