Audi S7 Power Loss & Rough Running: Common Fixes

I had nearly identical issues with my 2017 Audi S6. Based on some experience working on cars, the symptoms you describe match what I encountered, poor performance, rough running, and check engine light. After checking the air-fuel ratio and running diagnostics, my workshop found a faulty fuel injector that was causing inconsistent fuel delivery. This explained the lean running condition and power issues. The repair involved replacing the defective injector and testing the other injectors to ensure proper spray pattern. Total cost was 515 Euro including parts and labor. The throttle body and oxygen sensor readings were also checked during diagnosis, as these components can cause similar symptoms. However, the root cause was confirmed to be the injector issue. To provide more targeted advice, could you share: Current mileage on your S7, Whether the check engine light is solid or flashing, If you notice the symptoms more during cold starts or when the engine is warm, Any unusual sounds or vibrations, Recent maintenance history This information would help determine if your case matches what I experienced or might point to other potential causes.

Thanks for sharing your experience. My S7 has 40204 KM and was last serviced 3 months ago. The check engine light is solid, not flashing, and the symptoms are most noticeable after the engine warms up. Your fuel injector issue sounds very similar to what I am experiencing. The jerking and power loss match exactly. I will definitely have the workshop check the fuel delivery system first. Did you notice any specific fuel consumption changes before the injector failed? Also, was your repair done under warranty, since the 515 Euro cost seems relatively low for injector work?

Thanks for the additional details about your S7. The symptoms do sound nearly identical to what I experienced. Yes, I noticed about a 15-20% increase in fuel consumption about two weeks before the injector completely failed. This is typical when the engine runs lean, as it tries to compensate for the inconsistent fuel delivery. My repair was not under warranty, but I was fortunate that only one injector needed replacement. The mass air flow sensor and oxygen sensor readings helped pinpoint the specific faulty injector, which saved diagnostic time and costs. If multiple injectors need replacement, the cost can easily exceed 1500 Euro. After the repair, my S6 returned to normal operation immediately. The check engine light cleared, power was restored, and the engine ran smoothly again. The throttle response also improved significantly. Based on your mileage and symptoms appearing after warm-up, I strongly suspect you are dealing with a similar injector issue. The intake manifold and other components typically show different behavior patterns. Make sure your workshop performs a complete fuel system diagnostic, including checking injector spray patterns and fuel pressure.

Thanks for all the helpful input. After reading about your experience, I am more confident about the direction to take with my S7. The matching symptoms, especially the performance issues after warm-up, make me think we are dealing with the same problem. I will ask my workshop to focus on the fuel system first, particularly the injectors. I appreciate the tip about checking fuel pressure and spray patterns, will make sure they include that in their diagnostic process. Good to know about the potential cost range too, depending on whether it is one or multiple injectors needing replacement. One final question, after your repair, did you need to make any changes to your driving habits or maintenance schedule to prevent the issue from recurring? I want to avoid similar problems in the future with my S7.