SQ5 DPF Sensor Issues Cause Regen & Smoke Problems

Had this exact issue with my 2020 Q5 diesel. Vehicle diagnostics revealed a faulty exhaust back pressure sensor, which was causing similar DPF problems and emission control issues. After experiencing black smoke during acceleration and constant DPF warnings, I took it to a workshop. The pressure sensor was completely shot, preventing proper exhaust system monitoring. The repair involved replacing the sensor and running a complete DPF regeneration cycle. Total cost was 245 Euro including parts and labor. The vehicle emissions returned to normal after the fix, and engine performance improved noticeably. No more warning lights or failed regeneration attempts since then. What engine variant does your SQ5 have? This could help determine if the repair process would be similar. Also, have you noticed any changes in fuel consumption or engine performance besides the smoke and warning lights? Knowing these details would help compare if your situation matches what I experienced with the pressure sensor failure.

Just had my 82610 KM service done last month and started experiencing these issues shortly after. Good to hear replacing the exhaust sensor fixed it for you. My fuel consumption has increased by about 2L/100km and the engine feels sluggish, especially during cold starts. The auto repair shop quoted 290 Euro for diagnostics and sensor replacement. The exhaust system seems to make a slight whistling noise during acceleration too. Did you notice anything similar before your repair? Wondering if I should also request a full emission control system check while they have it in the shop.

Thanks for the additional details about your SQ5. Your symptoms match exactly what I experienced, including that whistling noise during acceleration. That specific sound was actually a clear indicator of the pressure sensor issue in my case. The increased fuel consumption matches my experience too. I noticed around 2.5L/100km higher consumption before getting the repair done. The car maintenance report showed the exhaust sensor failure was causing the engine to run rich, explaining both the fuel economy drop and the black smoke. When I had mine fixed, I did opt for the full emission control system check. It was worth the extra cost since they found some carbon buildup in the exhaust system that needed cleaning. The complete service included: Pressure sensor replacement, Full emission control system inspection, DPF cleaning and forced regeneration, Vehicle diagnostics system reset Total cost came to 410 Euro, but it solved all issues completely. The engine response went back to normal, and fuel consumption returned to standard levels within 2 tanks of fuel. Since your mileage and symptoms are nearly identical to what I experienced, I would recommend getting the full system check. The whistling noise particularly concerns me as it could indicate additional exhaust system issues beyond just the sensor.

Given the details about my SQ5 and comparing it with your experience, I appreciate the thorough information. Since my symptoms match yours so closely, especially the whistling noise and increased fuel consumption, I will definitely go ahead with the full emission control system inspection you suggested. My mechanic can fit me in next week, and I will request the complete service package including the pressure sensor replacement, system check, and DPF cleaning. The 410 Euro cost seems reasonable considering the comprehensive work involved and the potential for preventing future exhaust system problems. The sluggish performance and vehicle diagnostics warnings are becoming more noticeable, so getting this fixed soon makes sense. Will update this thread after the repair to confirm if replacing the pressure sensor and cleaning the system resolves my engine performance issues. Thanks for sharing your experience, it helped narrow down the probable cause and gave me a clear repair path forward.