SQ8 Engine Stalling Points to Critical Fuel Mix Issue

I experienced similar symptoms with my 2020 S7. The stalling and check engine light pointed to fuel system issues, but it turned out to be a faulty fuel pressure sensor connection. The symptoms match what you describe, rough idle, stalling, and fuel mixture codes. While fuel contamination can cause these issues, the sensor connections often fail first. In my case, the connector had corroded, causing incorrect readings and making the engine management system run an improper fuel mixture. The repair involved cleaning the connector and replacing the wiring harness section. This wasn't a major repair that affected the combustion chamber or required fuel system cleaning. The technician confirmed the fuel quality wasn't the issue after testing. Worth checking the simple things first, your symptoms align more with an electrical connection problem than wrong fuel use. A diagnostic scan should quickly identify if its a sensor issue versus actual fuel economy or contamination problems. A proper inspection can rule out serious engine damage. These symptoms dont typically indicate internal engine problems if caught early.

Thanks for checking this. This sounds a lot like what was happening to my Audi SQ8. After dealing with similar stalling issues, my mechanic also found corroded connections rather than actual fuel system problems. The engine knock I was worried about turned out to be unrelated. Curious, do you remember what the total repair cost was? I paid 450 Euro for the full diagnostic work and connector replacement, including a preventive fuel filter change. Have you had any recurring issues since the fix? In my case, everything has been running smoothly for about 6 months now. The mechanic said these connection problems are more common than actual fuel quality issues, which was reassuring to hear.

After the mechanic fixed the defective cable connection on my S7, the fuel mixture problems completely disappeared. They charged 95 Euro for the repair work, which was much less than your full service since they only needed to address the connector issue. The diagnostic quickly revealed the incorrect fuel composition readings were caused by the faulty sensor connection rather than actual fuel contamination. The car has been running perfectly for over a year now with no fuel-related warning lights or stalling. Like your mechanic mentioned, these sensor connection problems happen more frequently than actual fuel quality issues. The fuel filter typically isnt the culprit when the symptoms appear this suddenly, its usually electrical. Good to hear your SQ8 is back to normal operation. These connection problems can be worrying when they first appear, but theyre typically straightforward to fix once properly diagnosed.

Had a similar story to share with my car. Took it to the mechanic last week worried about potential engine damage. The symptoms matched exactly, stalling, check engine light, and funky idle. Was convinced Id gotten bad gas or messed up the fuel mixture somehow. Turns out the fuel system was fine. The mechanic found corroded wiring near the fuel pressure sensor causing false readings. Total bill came to 380 Euro for diagnosis, cleaning, and replacing that section of the harness. They inspected the fuel filter too but it was clean. Car has been running perfectly since the fix. The mechanic explained these connection issues are way more common than actual contaminated fuel problems. Really relieved it wasnt serious engine damage like I initially feared. Just sharing since your situation sounds identical to what I dealt with.