Skoda Roomster diesel increased fuel consumption and poor starting

Interesting. I had a similar issue with my Roomster some time ago. Higher fuel consumption and poor starting. Did you check the throttle position sensor? Is the engine throttle responding correctly?

The throttle position sensor readings appear normal, however, the correlation between accelerator pedal position and throttle body opening seems inconsistent. Could this be indicative of an issue with the accelerator pedal module itself?

Yes, the symptoms you describe align with what I experienced. The inconsistent throttle response points towards the accelerator pedal module. While throttle cleaning might offer temporary improvement, I suspect the underlying issue persists. I recommend a workshop visit for confirmation.

The defective accelerator pedal module was indeed the culprit. Replacement completed at a cost of 205€. Fuel consumption appears to be returning to normal.