Seat Alhambra Diesel Filter Problem

I encountered a similar predicament with my Alhambra, although the engine type was similar to yours. The symptoms you describe, reduced engine power coupled with visible smoke during acceleration, strongly suggest a potential issue with the diesel particulate filter (DPF). Have you observed any warning lights illuminated on the dashboard? Specifically, a DPF warning light?

Warning lights? Yes, a light came on that looked like an exhaust pipe with dots in it, but it disappeared after a while. Also, is a diesel filter expensive? What does backpressure mean? Like, is it similar to when you try to blow up a balloon that's too full?

The intermittent illumination of the DPF warning light further corroborates the hypothesis of a defective diesel particulate filter. Backpressure, in this context, denotes the resistance to exhaust gas flow within the filter. Your analogy to an overinflated balloon is conceptually accurate. Regarding costs, filter replacement can be a substantial expense. A sensor fault might also be present. I strongly suggest a diagnostic evaluation at a reputable workshop. Do not delay.

You're a lifesaver! I took it to a trusted mechanic, and it was indeed the diesel filter. The backpressure was through the roof! Filter replacement, sensor fault cleared, and now she's running like new. Cost me around 1550€, ouch! But worth it to have my Alhambra back in action. Thanks again for your help!