Skoda Scala Diesel Injection Issue

Sounds like a clogged injector. Had a similar issue with my old Renault Megane. Symptoms were nearly identical. Have you tried using any fuel injector cleaner additives? Sometimes that can help clear things out, though it's a bit of a gamble.

I have not used any additives yet. Is it possible that a dirty injection valve can cause such a significant reduction in performance and higher fuel consumption? Could this also be related to the vehicle sometimes stalling at idle?

Yes, absolutely. A dirty injector can definitely cause all those problems. When the injector isn't spraying fuel correctly (atomizing it), the engine doesn't burn fuel efficiently. This leads to reduced power, poor fuel economy, rough idling, and potential stalling. The unburnt fuel also increases emissions. While an additive might help, with those symptoms, especially the stalling, it's probably best to have a workshop take a look. They can test the injectors and see if they need cleaning or replacement.

Thank you for the insights. I took the vehicle to a workshop and they confirmed the defective injection nozzle. The repair, including parts and labor, cost 515€. Hopefully, this resolves the poor starting, fuel consumption, and performance issues. The mechanic mentioned this is important for emissions as well.