VW Lupo Diesel: DPF Pressure Drop Causing Power Loss

Had similar issues with my 2007 VW Polo TDI. The symptoms match exactly what I experienced, reduced power, excessive smoke, and warning lights related to the exhaust system. The root cause was a faulty exhaust back pressure sensor, which was causing DPF issues and incorrect DPF regeneration cycles. The emission control system was basically getting false readings, leading to incomplete burns of collected soot. The repair involved: Replacing the defective pressure sensor, Cleaning the DPF filter, Performing a forced DPF regeneration, Updating the engine management software This was a serious issue that required immediate attention, as continuing to drive with these symptoms risks permanent DPF damage and further reduced power output. The complete repair took about 6 hours at the workshop. The car returned to normal performance after the fix, no more smoke, full power restored, and warning lights cleared. The exhaust system has been working properly since then, with no recurring DPF issues over the next 40000km. A certified diesel specialist should properly diagnose this using diagnostic equipment to confirm the exact fault codes before starting repairs.

Thanks for sharing your experience with the VW Polo. Your symptoms do sound spot-on with what I faced. Just curious, do you remember roughly how much you paid for all those repairs? My Lupo is still showing low pressure warnings and reduced power after a basic service, so I might need similar work done. Also, has everything stayed working properly since the fix, or have you noticed any other diesel exhaust issues popping up?

Since getting the repairs done, everything has been running perfectly, no more diesel exhaust issues or warning lights. The low pressure problem in the particulate filter was completely resolved after replacing the faulty exhaust back pressure sensor. The total repair cost was 245€, which covered both parts and labor. This might seem steep, but considering the alternative of complete DPF failure, it was worth addressing quickly. The emission control system now works as intended, with proper regeneration cycles and no reduced power problems. The car has performed reliably for several months now with no recurring exhaust system faults. Full power was restored immediately after the fix, and fuel consumption returned to normal levels. If your Lupo is showing similar symptoms, getting the pressure sensor checked would be a good starting point.

Thanks for the advice. Finally got my Lupo fixed last week at a diesel specialist workshop. They found both a faulty pressure sensor and a partially blocked DPF causing the emission control problems. The total repair came to 320€ including: New pressure sensor, Professional DPF cleaning, System diagnostics, Labor costs The difference in performance is remarkable. No more warning lights, power has returned to normal, and the excessive smoke is completely gone. The DPF regeneration is now working properly according to the mechanics diagnostic report. Best decision was switching to a specialist workshop. They actually took time to properly diagnose the reduced power issues instead of just doing a basic service. After 500km of driving, everything is still working perfectly with no diesel engine problems. For anyone facing similar symptoms, getting proper diagnostics from a diesel expert is worth the initial consultation cost. Trying to save money with basic servicing actually ended up costing me more in the long run.