Diesel Power Loss & Smoke: DPF Issues Fixed Inside

As someone with moderate experience maintaining diesel vehicles, I had a very similar issue with my 2003 Audi A4 diesel about a year ago. The symptoms you describe match exactly what I experienced, reduced power and smoke during acceleration. After a vehicle inspection, my workshop confirmed the diesel particulate filter was completely clogged and beyond cleaning. They explained that attempting regeneration would not solve the problem due to the filter's condition. The exhaust system needed proper attention to prevent further engine issues. The complete repair included: Removing the old DPF, Installing a new filter, Resetting the engine management system, Testing fuel efficiency post-repair Total cost was 1550 Euro, but the improvement in performance was immediately noticeable. The engine runs smoother now and fuel efficiency is back to normal levels. Before suggesting specific solutions, could you share: Current mileage on your A3? How long have you noticed these symptoms? Any previous DPF maintenance history? Do you mainly drive short or long distances? This information would help determine if cleaning might still be an option in your case or if replacement is necessary.

Thanks for the feedback. My A3 has 166884 KM on the clock and had its last major service 6 months ago. The smoke and power issues started about 3 weeks ago. The car gets used daily for longer trips, so the exhaust system usually has good chances to reach proper operating temperature. The workshop did a sensor fault check during the last service but found no issues with the DPF back then. No regeneration was needed at that point. Interesting that you mention the cost, a local shop quoted me 1200 Euro for a full replacement, which seems reasonable compared to your experience.

Thanks for providing those details. Based on your mileage and usage pattern, your situation seems less severe than what I faced with my A4. Since you do regular longer trips, your DPF has better opportunities for natural regeneration compared to my mainly city driving pattern. The fact that no sensor fault was detected 6 months ago, and the symptoms only appeared recently, suggests your DPF might still be salvageable through professional cleaning rather than requiring full replacement. When my filter failed, the symptoms had been gradually worsening over several months. In my case, waiting too long led to the higher 1550 Euro replacement cost. The 1200 Euro quote you received for replacement is competitive, but I would recommend first exploring a professional DPF cleaning service, which typically costs between 300-500 Euro. My mechanic later told me that catching these issues early often means cleaning can restore proper function. Given your regular highway driving and relatively recent clear sensor readings, starting with cleaning could save you significant money while resolving the power and smoke issues. Just ensure the workshop performs a thorough exhaust system inspection to rule out any other contributing factors before proceeding.

My situation does seem less severe than yours, and your suggestion about trying the cleaning first makes a lot of sense. The backpressure issues and smoke are definitely concerning, but with my regular longer trips allowing for proper regeneration cycles, I will explore the cleaning option first. I contacted another workshop that specializes in exhaust system maintenance, and they offered a complete DPF cleaning service with diagnostic testing for 400 Euro. This seems like a reasonable starting point given the circumstances. They mentioned they would perform a full vehicle inspection first to ensure no other components are affecting the DPF performance. If the cleaning doesnt improve the fuel efficiency and resolve the power issues, I can always proceed with the full replacement option later. At least this way, I am taking a systematic approach to the repair process rather than jumping straight to the most expensive solution. Will book the cleaning service for next week and update if anyone else faces similar issues in the future.