SQ8 Engine Issues: MAF Sensor & Power Loss Alert

Similar issues occurred on my 2020 Q8 last summer. With some experience working on VAG engines, I noticed comparable symptoms, especially the rough idle and inconsistent power delivery. Turned out the fuel injection system was the culprit. After diagnostic testing, the workshop found a faulty injector that was causing an improper air-fuel ratio. The rich mixture was triggering the oxygen sensor, leading to the check engine light and performance issues. The repair involved: Complete diagnostic scan, Fuel injector replacement, System pressure testing, Intake manifold inspection, ECU adaptation Total cost was 515 Euro including parts and labor. The car has run perfectly since the repair, with smooth idle and proper acceleration. Could you share: Current mileage? Any recent maintenance history? Specific fuel type you usually use? When did the symptoms first appear? Are there any unusual sounds from the engine bay? This information would help determine if your issue matches what I experienced and could guide you toward the right solution.

Thanks for the detailed feedback. My SQ8 has 127337 KM and last service was just completed 2 weeks ago. The symptoms started right after that service. No unusual sounds, but I did notice the throttle body seems to be responding erratically. The spark plugs were changed during the service, which makes me wonder if they could be related to the problem. Interesting point about the rich mixture, my onboard computer is showing similar symptoms to what you described. Will get those fuel injectors checked out since the issues seem very similar to what you experienced.

Thanks for the additional details about your SQ8. Since my repair experience, I learned that post-service issues like yours often point to either installation problems or parts compatibility. The throttle body response issues combined with the new spark plugs timing is significant. After my fuel injector fix, I discovered that modern engines are particularly sensitive to the interaction between the throttle body, mass airflow sensor, and spark plug systems. A poorly seated spark plug or incorrect gap setting can create symptoms nearly identical to fuel delivery problems. In my case, before discovering the faulty injector, the workshop initially suspected the new spark plugs were the cause of the rich mixture condition. They tested the throttle body operation and found it was actually responding to corrections being made by the oxygen sensor trying to compensate for the fuel delivery issue. Given your symptoms started after the service, I would recommend: 1. Having the spark plug installation double-checked 2. Getting the throttle body operation verified 3. Then moving on to fuel injector diagnostics if needed The service timing suggests this might be a simpler fix than my situation. My repair costs could have been lower if we had checked these basic items first.

My SQ8 problem has been resolved, wanted to update everyone who helped. After taking it back to the shop, they found that one of the new spark plugs was indeed improperly gapped, causing erratic signals to the oxygen sensor. This led to the catalytic converter getting excessive fuel and the ECU constantly trying to adjust the air-fuel ratio. The fix was straightforward: Regapped all spark plugs, Cleaned the mass airflow sensor, Reset ECU adaptations, Verified proper intake manifold operation Total cost was 180 Euro for diagnostic and labor. The engine now runs perfectly, smooth idle, proper power delivery, and no check engine light. Really glad it wasnt the fuel injectors after all. Great reminder to always start with the basics, especially when problems begin right after service. Thanks for helping me narrow down the possible causes and saving me from potentially unnecessary repairs.