RSQ3 Engine Stalling Issues Due to Rail Pressure Sensor

Had a similar issue with my 2018 RS3 last summer. Have some experience working on cars but mostly basic maintenance stuff. The symptoms you describe match exactly what happened with mine, engine stalling at idle and significant power loss. The fuel rail pressure sensor was indeed the problem, causing irregular fuel injection patterns. Took it to my regular workshop after attempting basic diagnostics at home. They confirmed the faulty pressure sensor was disrupting proper fuel delivery. The repair included replacing the sensor and running a complete diagnostic check of the fuel injection system. Total cost came to 240 Euro including parts and labor. The fix completely resolved the stalling and power issues. Engine runs smooth as new now. Before suggesting more specific advice, could you share: Current mileage on your RSQ3? Any modifications to the fuel system? When was the last fuel system service done? Any other warning lights besides check engine? This information would help determine if your case matches mine and whether you might need additional checks.

Thanks for sharing your experience. My RSQ3 has 45376 KM on the odometer and got its last service 3 months ago. Also checked the fuel injection system during that service and everything was fine then. The check engine light is the only warning light active right now. Engine performance has definitely dropped compared to normal operation. No modifications have been done to the fuel rail or any other engine components, everything is still stock. Would you recommend going straight to a workshop for diagnostics, or is there anything I should check first? A 240 Euro repair bill sounds reasonable if it fixes these issues.

Thanks for providing those details. Since your car is still stock like mine was and showing identical symptoms, I strongly suspect the same rail pressure sensor issue, especially since problems developed even after a recent service. On my RS3, I first tried checking the sensor signal with an OBD reader, but the workshop's professional diagnostic equipment ultimately provided much more accurate fuel rail pressure readings. Given the similarity of our cases and the critical nature of the fuel injection system, I recommend going directly to a workshop. The 240 Euro I paid was fair considering the diagnostic work and sensor replacement. Just make sure they perform a complete fuel system check once the new pressure sensor is installed, this was key in my case to ensure there were no underlying issues affecting the fuel rail. Even with low mileage, these sensors can occasionally fail due to normal wear or fuel quality variations. The repair should fully restore your engine performance and eliminate the stalling, just like it did on my RS3. Would you like me to share any specific details about the repair process or the post-fix performance improvements I experienced?

Based on your experience and symptoms, I will definitely take it to a workshop for proper diagnostics. Having a professional check the fuel rail pressure sensor seems like the logical first step, especially since the issues match what you encountered. The stock configuration and similar behavior of our cars makes me confident we are dealing with the same problem. Your advice about getting a complete fuel system inspection after sensor replacement makes a lot of sense to ensure everything is functioning correctly. I will schedule an appointment with my regular workshop this week. The 240 Euro repair cost seems reasonable for parts and labor if it resolves both the stalling and power loss issues. Will update the forum once I get it checked out and repaired in case anyone else encounters similar fuel injection system problems in the future. Thanks again for the detailed information about your experience. It really helped confirm my initial diagnosis and gives me confidence about the repair path forward.