Q7 Fuel Rail Pressure Sensor Issues & Stalling Problems

Had a similar issue with my 2009 Q5 a while back. Have some experience working on cars but needed professional help with this one. The symptoms matched exactly, engine stalling at idle, poor performance, and that annoying check engine light. The fuel pressure sensor ended up being the culprit. When the pressure sensor fails, it sends incorrect readings to the ECU, causing the engine to get improper fuel amounts. Took it to a workshop where they first ran diagnostics to confirm the rail pressure sensor was faulty. The entire fix, including parts and labor, cost me 240 Euro. They also checked the fuel pump and fuel lines while they were at it, which is important since a failing sensor can sometimes mask other fuel system issues. The repair solved all issues, no more stalling, performance returned to normal, and the check engine light cleared up. These pressure sensors are actually a known weak point in these engines. What engine variant does your Q7 have? Would help to know if its the same powertrain to share more specific details about the repair process. Also, have you noticed any other symptoms, like rough idling or hesitation during acceleration?

Last service was done at 56905 KM and the check engine light issue appeared shortly after. The sensor signal readings from the diagnostic scan confirm unusual fuel pressure fluctuations. My mechanic mentioned testing both the low and high pressure fuel system components to rule out any related issues. Like others suggested, the symptoms match the classic pressure sensor failure pattern, inconsistent engine performance and frequent stalling. Going to schedule a complete fuel system inspection next week. Will update once I get concrete diagnostic results. Would appreciate insight from anyone who has tips on preventive maintenance to avoid similar sensor failures in the future.

Thanks for the update on your Q7 situation. After having the same repair done on my Q5, I learned a lot about maintaining proper fuel system health. The fuel pressure fluctuations you mentioned from the diagnostic scan are very similar to what I experienced. My sensor readings were all over the place before the repair, causing the diesel engine to run extremely rough. Since my repair, I've made some changes to avoid future issues with engine performance: Using high-quality fuel from reputable stations, Changing fuel filters at recommended intervals, Not letting the tank run too low, as it can stress the fuel injection system My mechanic explained that contaminated fuel often contributes to sensor failures. The high pressure fuel system is particularly sensitive to fuel quality issues. Based on your mileage, its worth having them check the entire fuel delivery system while they diagnose the pressure sensor. In my case, catching the failing sensor early prevented damage to other fuel system components. Keep us updated on what they find during the inspection. The good news is once properly diagnosed and repaired, these issues typically dont return if you stay on top of maintenance.

Thanks for the helpful feedback everyone. Just wanted to give a quick update on my Q7 situation. My mechanic completed the diagnostic work today and confirmed what we suspected. The fuel rail pressure sensor is indeed failing, showing erratic readings that match the engine stalling and performance issues. The inspection revealed no other major fuel system problems, which is a relief. The repair quote came in at 260 Euro including parts and labor. They recommended replacing both the high and low pressure sensors as a preventive measure since theyll already be working on the system. Makes sense given the age of the vehicle. The check engine light and inconsistent engine performance have become more frequent, so Im scheduling the repair for next week. Will definitely follow the maintenance advice about fuel quality and regular filter changes to prevent future issues. Looking forward to having this resolved and getting back to normal engine operation without the constant worry of stalling. Will post another update once the repair is complete to confirm if it fully resolved the symptoms.