Audi SQ7 MAF Sensor Issues Causing Multiple Problems

Had similar issues with my 2018 Audi Q7 TDI. With some experience working on cars, I first noticed performance decline and engine stalling, particularly at idle. The check engine light came on, which prompted me to take it to a workshop. The mechanics ran diagnostics that showed the mass air flow sensor was sending incorrect readings, affecting the air-fuel ratio. They first attempted cleaning the air intake and MAF sensor, but the issues persisted. Complete sensor replacement was ultimately needed. Total repair cost was 365 Euro, including parts and labor. Since the replacement, fuel economy returned to normal and all symptoms disappeared. For a more accurate comparison with your situation, could you share: Current mileage, When symptoms first appeared, Whether you notice any specific driving conditions making it worse, If you recently changed the air filter, What error codes your check engine light is showing This information would help determine if your case matches what I experienced and whether you might need similar repairs.

Last service completed at 24329 KM. My symptoms started about 2 weeks ago, getting worse in cold starts. The CEL shows P0101 code. Haven't changed the air filter since purchase. Things get particularly bad during highway driving, especially when the mass air flow readings seem most inconsistent. Fuel economy has dropped from 8.5 to nearly 11 liters per 100km, and sensor failure seems most likely given the diagnostic pattern. The performance decline is quite noticeable during acceleration.

Having gone through this exact situation with my Q7, your P0101 code and symptoms perfectly match what I experienced. The mass air flow sensor deterioration on these models often shows up most dramatically during cold starts and highway speeds, just as youre describing. That fuel economy drop from 8.5 to 11 L/100km is remarkably similar to what I saw before the repair. The fact that your air filter hasnt been changed could be contributing to the MAF sensor issues, as dirty filters can accelerate sensor wear. After my sensor replacement, I established a more frequent maintenance schedule for the air intake system. Changing the air filter every 20000km and regular MAF sensor cleaning has prevented any recurrence of these issues. Looking at your case, I strongly suspect youll need a full sensor replacement like I did. The cleaning attempt in my case provided temporary improvement but ultimately wasnt enough. With similar mileage and symptoms, plus identical performance decline patterns, your diagnosis appears clear. Consider having both the MAF sensor replaced and the air filter changed at the same time to restore proper air intake function and fuel economy.

Thanks for the detailed info, that P0101 code and the symptoms you described pretty much confirm my suspicions about the mass air flow sensor. My SQ7 is currently at 28000 KM, so not far from your mileage point when issues started. Really helpful to hear that changing the air filter along with the MAF sensor gave you a complete fix. My biggest concern was the sudden increase in fuel consumption matching what you experienced. Given how the check engine light behavior and engine stalling patterns are identical, I'll go ahead with both the sensor replacement and air filter change. The performance issues during highway driving and cold starts are too similar to ignore. I appreciate the maintenance schedule advice too. Setting up regular air filter changes every 20000km makes a lot of sense to prevent future air-fuel ratio problems. I'll make sure to keep track of how the fix improves things and update this thread with the results after the repair.