Skoda Rapid Diesel Smoke on Acceleration

A faulty exhaust back pressure sensor definitely aligns with those symptoms. When it fails, the ECU receives incorrect readings, leading to issues with engine performance and DPF regeneration. Have you checked the sensor's wiring and connections for any obvious damage or corrosion?

Where exactly is the exhaust sensor located? I want to check those connections before I consider replacing it.

The exhaust back pressure sensor is typically located either on the diesel particulate filter itself or somewhere along the exhaust system, prior to the DPF. Given the symptoms and your suspicion, it’s best to have a workshop confirm the diagnosis before replacing any parts. An auto repair shop will be able to pinpoint the issue with certainty.

The exhaust back pressure sensor is replaced. The total cost was 245€. Engine performance is back to normal, no more smoke, and the DPF is regenerating again. Thanks for the help.