Modus engine power loss

I had similar symptoms with my Modus. Have you checked the knock sensor, and what fuel octane are you using?

I haven't checked the knock sensor yet. I'm using standard unleaded fuel, the same as always. Could the fuel octane level be causing the knocking? I am not familiar with engine tuning, could that be the issue, too?

The fuel octane could be a factor. But with the smoke and error code, deposits in the combustion chamber seem likely, and a faulty knock sensor is also possible. I'd recommend taking it to a workshop for a proper diagnosis and cleaning of the cylinder heads.

Thanks for the advice. I took it to a workshop as suggested, and it was deposits in the combustion chamber. A cleaning and some adjustments cost me 425€. The car runs like new again.