Modus Diesel Engine Power Loss

Hey! That sounds frustrating. A mixture preparation error could be caused by a few things. Have you checked the oxygen sensor? A faulty one can really mess with the air-fuel ratio. It could also be related to your fuel injection system. Is the exhaust smelling particularly rich? When was the last time you changed your spark plugs? Although, on a diesel it's glow plugs we should be looking at. These can impact mixture and running if they're not performing well!

Thanks for the suggestions. Is there a way to test the oxygen sensor without specialized equipment? Also, if the fuel injection system is the problem, what specific components should I check first?

Testing the oxygen sensor properly usually needs a multimeter to check the voltage output – not super specialized, but you need the tool. As for the fuel injection, that's trickier. Given all the symptoms, especially the stalling, combined with the mileage, a defective injector is a prime suspect. Honestly, with those symptoms, you're probably best off taking it to a workshop before you end up causing more damage!

Thanks for the advice. I took the car to a local workshop based on your recommendation. They confirmed that the injector was defective. The repair cost came to 515€.