Audi S3 Stalling: Fuel Regulator Fix Guide + Costs

Had identical symptoms with my 2016 Audi S4. The rough idle and power loss turned out to be more complex than just the fuel pressure regulator. After changing the fuel filter, the engine misfire persisted, and diagnostic tests revealed a failing fuel pressure sensor along with a clogged fuel regulator. The pressure drop was significant enough to trigger multiple error codes. The technician found that debris from the old fuel filter had partially blocked the regulator, causing inconsistent fuel delivery. The complete repair required: Replacing fuel pressure sensor, Installing new fuel regulator, Cleaning fuel rails, Full system diagnostic This was a serious issue that could have led to complete engine failure if left unaddressed. The repair took about 6 hours total, including diagnostic time and pressure testing to ensure proper fuel system operation. A proper fix requires specialized diagnostic equipment to verify fuel pressure readings. Would strongly recommend having this done at a shop with Audi-specific diagnostic tools, as incorrect diagnosis can lead to replacing parts unnecessarily.

Thanks for sharing those details. My fix was similar, the fuel pressure sensor and regulator also needed replacement on my S3. Would be really helpful to know what you ended up paying for the full repair, since prices seem to vary quite a bit. Also curious if youve had any fuel efficiency issues or check engine light problems since the work was done? My car has been running smoother, but always good to know what to watch out for in the long run.

Thanks for asking about the follow-up. After the repairs, my S3 has been running perfectly with no check engine light issues. The fuel pressure regulator fix completely resolved the initial problems. Fuel efficiency actually improved slightly compared to when the system was failing. The total cost breakdown for my repair was around 750 Euro including: Fuel pressure regulator replacement, Labor costs, System diagnostics, Clearing error codes Had to return once to have them clear a lingering error code after the fuel filter change, which cost an extra 45 Euro, but that was minor compared to the main repair. The key is that all the fuel rail components are now working together properly. No engine misfire issues since then, and the idle is consistently smooth. If your repair was similar to mine, you should be in good shape for the long run.

I finally took my S3 to a reliable Audi specialist who diagnosed and fixed everything in one go. The fuel pressure sensor and regulator both needed replacement, just like you mentioned. Total bill came to 820 Euro which included parts, labor and system diagnostics. Its been about 3 weeks since the repair. The check engine light hasnt come back on and the car runs way better than before. Idle is smooth and power delivery is back to normal. Fuel consumption has actually improved a bit too. The whole job took about 5 hours at the shop. They did a thorough check of the entire fuel rail system and cleaned out some debris while they were at it. Much better experience than my previous mechanic who just wanted to replace unusual parts without proper diagnosis. Glad I found this forum thread, helped me understand what I was dealing with and avoid unnecessary repairs. Money well spent to get it done right the first time.