AMG GT hybrid exhaust issue resolved

That sounds rough! A faulty exhaust sensor could definitely mess with engine performance and emission control. If the sensor isn't reading the exhaust pressure correctly, the car's computer probably won't know how to properly manage the engine. Is the smoke black, blue, or white? And has your fuel economy decreased?

The smoke is black-ish, I think. And yeah, the fuel economy is terrible now! So, if it is the exhaust sensor, is it something that needs to be fixed right away, or can I delay it for a bit? I am asking because I am not sure I can afford the car maintenance right now…

Black smoke and terrible fuel economy definitely point to a problem with the engine running too rich – too much fuel, not enough air. A bad exhaust sensor could cause that. I wouldn't risk driving it too much longer. You could damage the engine or the DPF. You should get it to a workshop. Hopefully it is just the exhaust sensor!

I took it to the workshop, and you were right – it was the exhaust sensor. The bill came to 245€, which is annoying, but at least it wasn't worse. New sensor fitted, no more smoke, and the warning light is gone! Back to normal engine performance. Thanks again!