Audi A5 Power Loss and Smoke Points to EGR Crisis

I had a very similar issue with my 2016 Audi A4. As someone with some car maintenance experience, I recognized these symptoms immediately as potential EGR valve problems. The automotive repair shop confirmed my suspicions after running diagnostics. The symptoms you describe match exactly what I experienced, especially the power loss and increased fuel consumption. In my case, the EGR valve was completely jammed with carbon deposits, preventing proper exhaust gas recirculation and affecting the vehicle emissions control system. My workshop first attempted cleaning, but ultimately the EGR valve needed replacement. The total repair cost was 355 Euro, including parts and labor. The difference in performance after replacement was noticeable immediately, smoother idle, restored power, and normal fuel consumption. Before suggesting specific solutions, could you provide: Current mileage on your A5? Service history regarding the EGR system? Type of fuel you typically use? How long these symptoms have been present? This information would help determine if your situation requires cleaning or complete replacement of the EGR valve. These issues often vary depending on maintenance history and driving conditions.

Thanks for sharing your experience. My car has 171156 KM and had its last major service 4 months ago. After checking with various workshops, I discovered a vacuum leak was actually causing most of these issues, not the EGR valve as initially suspected. The rough idle and hissing sound were classic symptoms of a vacuum leak near the intake manifold. The workshop pressure tested the system and found a cracked hose. Repair cost was 180 Euro including parts and labor. After fixing the leak, the check engine light cleared and the engine runs smoothly again. This might be worth checking in your case too, as vacuum leaks can mimic EGR valve problems and affect vehicle emissions in similar ways.

Thanks for the update on your A5. This is really interesting because after I posted about my EGR valve experience, I actually discovered I had a combination of issues. While my EGR valve was indeed partially clogged, a vacuum leak was also contributing to the problems. The symptoms of vacuum leaks and EGR valve issues can be quite similar, affecting both engine performance and the emissions control system. In my case, the catalytic converter was also showing early signs of failure due to the improper air-fuel mixture caused by the vacuum leak. After the initial EGR valve replacement I mentioned, I still noticed some minor issues. A thorough inspection revealed a small crack in the vacuum line near the intake manifold, similar to what you found. The total additional repair for the vacuum leak was 165 Euro, and it made a noticeable difference in engine performance beyond what the EGR fix achieved. Your case reinforces the importance of comprehensive diagnostics. While exhaust gas recirculation problems are common in these engines, vacuum leaks can produce nearly identical symptoms. Its good to hear you got it sorted for a reasonable cost.

Good to provide closure on this issue. My A5 situation turned out differently than expected with the vacuum leak diagnosis. After 171156 KM, these things can happen, but Im glad it wasnt the more expensive EGR valve repair I initially feared. The comprehensive testing by the workshop definitely saved me money, showing that similar symptoms can have different causes. The vacuum leak repair at 180 Euro was much more reasonable than a full EGR valve replacement would have been. The immediate improvement in performance confirms it was the right diagnosis. For others with similar symptoms, my experience shows its worth checking for vacuum leaks first, as they can mimic EGR valve issues and affect vehicle emissions in similar ways. The hissing sound and rough idle were major clues that pointed to the vacuum leak rather than an exhaust gas recirculation problem. The repaired hose has completely resolved the power loss, smoke, and fuel consumption issues. Its been running perfectly for the past few weeks with no check engine light or other warning signs.