VW Lupo DPF Won't Regenerate, Sensor Issue Warning

Had almost the exact same issue with my 2006 VW Polo diesel last year. As someone with moderate DIY experience, I initially thought I could troubleshoot it myself, but the emission control system is quite complex. The symptoms matched yours perfectly, warning light, smoke, and failed regeneration attempts. The exhaust sensor was giving faulty readings, preventing proper DPF regeneration cycles. The pressure sensor malfunction was causing the whole exhaust system to operate incorrectly. Took it to a workshop where they ran complete vehicle diagnostics. The test immediately identified the faulty exhaust back pressure sensor. Total repair cost was 245€, including parts and labor. The whole job took about 3 hours. The fix made a huge difference, proper regeneration cycles resumed, smoke cleared up, and vehicle emissions returned to normal levels. Before suggesting more specific advice, could you share: Current mileage on your Lupo? When was the last DPF cleaning done? Any recent engine work or modifications? Are you mainly doing city driving or highway runs? This info would help determine if there might be other contributing factors beyond the pressure sensor issue.

Last service was at 147000km, and the symptoms started soon after. You raise good points about the diagnostic process. My driving pattern is mainly short trips, which probably hasnt helped the DPF situation. The exhaust sensor readings have been inconsistent according to the OBD scan I did at home. Engine performance definitely took a hit these past weeks. The quote from my local shop is actually higher at 380€. They mentioned the exhaust system might need additional work beyond just the pressure sensor replacement. But based on your experience with repair time and similar symptoms, maybe I should get a second opinion. Did your vehicle diagnostics show any additional fault codes besides the sensor issue? The shop keeps mentioning possible related problems that could drive up the cost.

Thanks for those details about your Lupo. My situation with the Polo was quite similar, my issues also started around the 150000km mark. The vehicle diagnostics on mine actually showed multiple fault codes. Besides the exhaust sensor error, there were codes related to the emission control system. However, replacing the pressure sensor resolved all codes, as the faulty readings were triggering false alarms in other systems. That 380€ quote does sound steep compared to my repair. The engine performance issues youre experiencing are nearly identical to what I faced, and they were all linked to the sensor malfunction. Those short trips definitely complicate DPF regeneration cycles, but the root cause seems to be the sensor. My mechanic initially suggested additional exhaust system work too, but I insisted on just replacing the sensor first. That turned out to be the right call, all symptoms cleared up after the sensor replacement. The smoke during acceleration stopped, and proper regeneration cycles resumed without any other repairs needed. Your OBD scan showing inconsistent exhaust sensor readings mirrors my experience exactly. If I were you, Id definitely get that second opinion, as this sounds like a straightforward sensor issue rather than a more complex exhaust system problem.

My initial concerns about the DPF and back pressure sensor seem spot on based on your repair experience. Really helpful to hear how the vehicle diagnostics pinpointed the exhaust sensor as the main culprit in your case. The short trips in my driving pattern definitely arent ideal for DPF maintenance, but the core issue does appear to be the sensor based on the similar symptoms and fault codes you described. Engine performance should improve once the sensor is working properly again. Think Ill follow your advice and get another workshop to check it out. That price difference between 245€ and 380€ is significant, especially if the exhaust sensor replacement alone could fix the problems. The car maintenance history is similar to yours too, with issues starting around the 150000km mark. Good to know that your additional fault codes cleared up after just the sensor fix. That gives me more confidence to question the extra work my shop is suggesting. Will update once I get that second opinion on the repair.