Audi Q5 Fuel Pressure Issues Causing Stalling & Power Loss

Having some experience with engine sensor issues, I dealt with almost identical symptoms on my 2012 Audi Q3 2.0T. The rail pressure issues and engine stalling were exactly what I experienced. After the check engine light appeared, I noticed the same problems, poor engine performance, especially during acceleration, and unusual stalling at idle. The diagnostic scan also pointed to the pressure sensor. My workshop confirmed the fuel rail pressure sensor was faulty and causing incorrect readings, which made the engine management system adjust fuel delivery incorrectly. They replaced the sensor, which resolved all symptoms. The repair cost 240 Euro including parts and labor. Before jumping to conclusions though, could you share: Full error code from your scanner, How long has this been happening, Any recent maintenance or repairs, Does it happen more when the engine is cold or warm These details would help confirm if your issue matches what I experienced. The symptoms definitely align with a faulty pressure sensor, but getting this additional information would help rule out other potential causes affecting engine performance.

Last service completed at 115000KM with full inspection. Had similar symptoms before but they went away after fuel system cleaning. Problem returned worse now. The error code is P0191 and engine stalling happens more frequently when warm. Started getting these issues right after refueling last week. No other maintenance done recently besides the routine oil changes and filter replacements. After monitoring fuel injection behavior, I notice the engine runs really rough between 2000-3000 RPM where the rail pressure seems most unstable according to live data. Would check engine light patterns suggest checking other components before replacing the sensor?

Thanks for the additional details. Your symptoms mirror what I experienced, especially the rough running between 2000-3000 RPM where the fuel rail pressure fluctuates. The P0191 code is exactly what my Q3 showed. The fact that the issue temporarily improved after fuel system cleaning but returned worse suggests the fuel pressure sensor is likely failing intermittently. When my sensor was failing, cleaning helped briefly because it improved the electrical contact, but the underlying sensor problem remained. My mechanic noticed the check engine light pattern matched a classic fuel rail pressure sensor failure, coming on during warm operation when pressure readings become most erratic. The sensor replacement fixed: The unstable rail pressure readings, Rough running at specific RPM ranges, Unusual stalling issues, Power loss during acceleration While a faulty pump or clogged filter can cause similar symptoms, the specific error code and behavior pattern strongly indicates a sensor issue. In my case, testing the fuel pressure confirmed the pump was working correctly, but the sensor was sending incorrect signals to the engine management system. Before replacing the sensor, have your fuel pressure tested to rule out actual pressure problems. This will confirm whether you are dealing with a sensor signal issue like I had or a mechanical fuel system problem.

The details from both responses really helped narrow things down. Makes sense that the fuel system cleaning only provided temporary relief if the sensor is the root cause. The matching error code and identical RPM range where problems occur is quite revealing. Going to have the shop test actual fuel pressure first to verify the pump is good, then proceed with the sensor replacement if pressure readings check out normal. The fact that similar issues were fully resolved with a sensor replacement on another 2.0T engine gives me confidence about this approach. Good call on documenting when the check engine light appears and how the engine performs during different operating conditions. Will make sure the workshop has all these details to avoid any misdiagnosis. Hoping the 240 Euro repair cost is in the same range at my local shop. Will update once I get the fuel pressure test results and confirm whether replacing the sensor fixes the engine stalling and performance problems. Thanks for sharing your experience with an almost identical situation.