SM5 rough engine and check engine light

Hey, that sounds familiar. I had similar symptoms with my old Opel Astra. Check engine light, poor throttle response and engine misfiring. Turned out to be the ignition coil. Have you checked yours?

Interesting. I was leaning towards fuel injectors. How did you diagnose the ignition coil issue?

Well, it was a process of elimination, but the garage confirmed it with some diagnostic tools. They checked the fuel injectors too but those were fine. Given your symptoms, it might be worth getting it checked professionally. Could be injectors, could be something else. Better safe than sorry.

Thanks for the advice. Took it to the shop, and you were right, it was the fuel injector. 515€ later and it runs like new again.