Audi RS3 Fuel System Failure Symptoms and Fix

Having dealt with similar symptoms on my 2013 S3, I can share my limited experience with fuel system repairs. These symptoms match what I encountered, rough idle, stalling, and reduced power with the check engine light illuminated. Initially thought it was the fuel pump, but it turned out to be much simpler. After changing my fuel filter, I experienced similar issues. The workshop discovered the fuel pressure sensor needed proper initialization with diagnostic equipment. The error entry was causing incorrect fuel pressure readings, leading to poor fuel efficiency and performance problems. The fix was straightforward, they cleared the error codes and performed a proper initialization of the fuel system sensors. Total cost was 45 Euro for diagnostics and reset. Before suggesting specific repairs, could you share: Current fuel pressure readings if you have them, Whether these issues started after any recent maintenance, If there are any specific error codes stored, Current fuel consumption compared to normal This would help determine if your issue matches what I experienced or if its something different in your fuel rail system.

Last service completed at 54969KM, experiencing ongoing pressure drop issues since then. The error codes you mentioned match my situation exactly. Based on the diagnostic readout, fuel pressure is fluctuating between 2.8-3.2 bar when it should be steady at 3.5 bar. Fuel consumption has increased by roughly 15% compared to normal. The fuel pressure sensor readings are definitely inconsistent, similar to what you described. Good to know about the initialization process, I had no idea the sensors needed recalibration after maintenance. The rough idle happens mainly during warm-up, which seems to align with your experience. Did your fix completely resolve the power delivery issues? My workshop quoted 350 Euro for a full fuel regulator replacement, so a sensor reset would be a much cheaper first step.

Thanks for sharing those pressure readings. Yes, in my case the initialization completely fixed both the engine misfire and power delivery problems. The fuel pressure stabilized right after the reset and has been steady at 3.5 bar since then. The 15% increase in fuel consumption you mentioned matches exactly what I experienced before the fix. These symptoms are classic signs of incorrect fuel pressure sensor calibration, especially following routine maintenance. A full regulator replacement for 350 Euro seems premature without first trying the sensor reset. The pressure drop you described between 2.8-3.2 bar is almost identical to my readings before the initialization. Given that the issues started after your service, its likely the same root cause. Would strongly suggest having the fuel pressure sensor initialized first. If the check engine light persists or the idle problems return after reset, then exploring the regulator replacement might make sense. In my case, its been 6 months since the reset with no fuel system issues or error codes returning.

The diagnostic feedback definitely matches my situation, really helpful to hear about the sensor initialization fixing similar symptoms. Makes total sense about trying that before jumping into the regulator replacement. Going to schedule the reset service this week since my pressure readings are nearly identical to what you experienced. Will start with the sensor calibration and monitor the check engine light and fuel pressure readings afterward. The rough idle during warm-up has been particularly annoying, so hoping this resolves it like in your case. Much rather spend 45 Euro on initialization than 350 Euro on a new regulator if not needed. Thanks for sharing the detailed pressure specifications and fuel consumption comparison. Will update once I get the sensor reset completed and see if it stabilizes at the proper 3.5 bar reading. The 15% higher fuel usage should hopefully return to normal as well if this fixes the fuel system pressure regulation.