S7 Rough Idle Points to Failing Fuel Pressure Sensor

Had the same symptoms on my 2012 Audi S5 with the fuel pressure sensor causing similar issues. The engine would stall at stops and run rough, especially during acceleration. The fuel delivery system was affected, causing inconsistent fuel flow to the injectors. Diagnosed through proper testing equipment, it revealed the fuel pressure sensor was sending incorrect readings to the ECU. This caused the engine to receive wrong fuel mixture calculations. The fuel pump was working fine, but the faulty sensor made the system think fuel pressure was too low. The repair involved replacing the fuel pressure sensor and checking all related wiring connections. While not the most expensive repair, it requires careful diagnosis since similar symptoms can point to multiple issues in the fuel delivery system. The fix restored smooth idle and resolved the stalling problem completely. This is actually a known issue on that generation of Audi engines. Getting it fixed quickly prevents potential damage to fuel injectors from improper fuel mixture. Most importantly, letting it go untreated risks complete engine stalling while driving. A professional diagnosis is crucial since fuel system issues can be complex. Having dealt with this personally, suggest getting it checked soon before it develops into a more serious problem.

Thanks for sharing your experience. Your symptoms match exactly what I went through with my S7. The erratic fuel delivery and check engine light were the key signs that led to discovering the faulty pressure sensor. Did you keep track of what the total repair cost was for your case? Also curious if youve had any recurring fuel system issues since the fix? Mine has been running smoothly for a while now, but always good to know what to watch out for.

Had the repair done just last week actually. The mechanic found and fixed a defective fuel pressure sensor exactly as suspected. Total bill came to 95 Euro for fixing a faulty cable connection, much less than expected since it didnt require replacing the entire sensor unit. Since the repair, the check engine light has stayed off and the rough idle completely disappeared. Fuel economy has notably improved too, and the jerky acceleration is gone. The engine now runs perfectly smooth at stoplights. No recurring fuel system issues in the weeks since the fix. The fuel injectors are working as they should with proper pressure readings now that the sensor is communicating correctly with the ECU. Based on what the tech mentioned, these pressure sensor connection problems rarely come back once properly repaired. Just keep an eye on your fuel economy and idle behavior as preventive maintenance. Any unusual changes in either could signal early fuel system problems, but with the cable connection properly fixed now, you should be good for the long run.

Thanks for the input. Just wanted to close the loop on my S7 situation. Took it to a different shop this time and they quickly identified the issue. True to what was suggested here, it was indeed the fuel pressure sensor acting up. The mechanic found some corroded wiring connections at the sensor, causing those erratic readings. Fixed the connections and replaced a worn gasket while they were in there. Bill came to 180 Euro total including diagnostic time. Way better than the wild estimates my previous shop was throwing around. Car runs perfectly now, no more rough idle or stalling. The fuel economy actually improved quite a bit too, which was an unexpected bonus. Really glad I got a second opinion and followed through on the repair before it led to bigger issues. Been about three weeks since the fix and everything is still running great. No check engine light, smooth acceleration, and perfect idle. Keeping an eye on things but seems like this common problem is now properly sorted.