Audi S5 DPF Failure Causing Power Loss and Smoke

Had similar symptoms with a 2017 Audi A5 diesel. The exhaust back pressure sensor was giving incorrect readings, causing DPF regeneration cycles to fail. The diesel engine would go into limp mode, showing reduced power and producing excessive smoke. A full diagnostic confirmed the pressure sensor malfunction was preventing proper DPF regeneration. The repair required: Replacing the faulty exhaust pressure sensor, Cleaning the DPF system, Performing a forced DPF regeneration, Resetting the engine management system This was a serious issue requiring immediate attention, as continued driving could have caused permanent DPF damage. The defective sensor readings were making the ECU think the diesel exhaust system was more clogged than it actually was. Key signs to watch for: Engine warning light, Drop in power above 2000 RPM, Excessive black smoke, Failed regeneration attempts, Higher than normal exhaust temperatures Recommend having a specialized diesel technician perform the diagnostics and repair. The pressure sensor replacement alone will not solve the issue if the DPF requires cleaning or regeneration.

Thanks for sharing your experience with the DPF issues. Same happened to my S5 last year and the symptoms match exactly. The reduced power and emission control problems were a real headache. Mind sharing what the total repair cost was in your case? Also curious if you had any other problems after fixing the low pressure sensor and DPF regeneration? My repair was done 8 months ago and so far everything runs smoothly, but always good to know what to watch out for long-term.

Since getting the exhaust back pressure sensor replaced on my A5 diesel, the emission control system has been working flawlessly. The repair cost came to 245 Euro for fixing the defective sensor, which was causing those frustrating DPF regeneration issues. The exhaust system now maintains proper pressure levels and the DPF regenerates normally. No more engine warning lights or power loss problems in the 8 months since the repair. The diesel exhaust flows correctly and the pressure readings stay within spec. For preventive maintenance, I make sure to take regular highway drives to help the DPF complete its regeneration cycles. The investment in fixing the pressure sensor was worth it to avoid more costly DPF damage down the line. The only advice I can give is to pay attention if the engine starts losing power again or if you notice changes in exhaust smoke, these are early warning signs of potential DPF pressure problems. But with proper maintenance, these systems are quite reliable once properly repaired.

Thanks everyone for the helpful input. I wanted to share how my repair experience turned out. After getting recommendations, I took my S5 to a certified diesel specialist who properly diagnosed the particulate filter issues. The mechanic found the exhaust pressure sensor was indeed faulty, causing incorrect readings and preventing proper regeneration. Total repair cost was 890 Euro which included: New pressure sensor, Complete DPF cleaning, System diagnostic, Forced regeneration cycle The reduced power problems disappeared immediately after repair. The exhaust system now works perfectly with no more dark smoke or strange smells. The engine performance returned to normal and the check engine light has stayed off. Big difference from my previous bad experience at another shop that wanted to replace the entire particulate filter for 2800 Euro. Really glad I got a second opinion from a proper diesel specialist. Lesson learned about finding the right mechanic who actually knows these systems.