Q7 Power Loss Issue: Troubleshooting Guide & Solutions

Had the same issue with my 2017 Q8 last summer. As someone with some experience working on cars, I first connected my scan tool to check the engine codes, but the multiple fault codes made it tricky to pinpoint the exact problem. The symptoms matched yours exactly, reduced power and check engine light. After some vehicle diagnostics, it turned out the issue stemmed from a faulty chip tuning installation by a third-party tuning shop. The engine control unit was showing conflicting signals due to incompatible software. Had to take it to a workshop where they removed the aftermarket tuning and reset the ECU to factory settings. The whole process took about 4 hours and cost 180 Euro. The car has been running perfectly since then. To help troubleshoot your case better, could you share: Have you had any recent modifications or tuning done? Which specific fault codes is your scanner showing? Does the reduced power happen gradually or suddenly? Any unusual sounds or vibrations? This could help determine if your issue is similar to what I experienced or if its something else entirely.

Had the same issue with my 2017 Q8 last summer. As someone with some experience working on cars, I first connected my scan tool to check the engine codes, but the multiple fault codes made it tricky to pinpoint the exact problem. The symptoms matched yours exactly, reduced power and check engine light. After some vehicle diagnostics, it turned out the issue stemmed from a faulty chip tuning installation by a third-party tuning shop. The engine control unit was showing conflicting signals due to incompatible software. Had to take it to a workshop where they removed the aftermarket tuning and reset the ECU to factory settings. The whole process took about 4 hours and cost 180 Euro. The car has been running perfectly since then. To help troubleshoot your case better, could you share: Have you had any recent modifications or tuning done? Which specific fault codes is your scanner showing? Does the reduced power happen gradually or suddenly? Any unusual sounds or vibrations? This could help determine if your issue is similar to what I experienced or if its something else entirely.

Thanks for sharing your experience. My car has been serviced regularly with the last maintenance at 25000 KM. The dashboard light appeared suddenly while driving on the highway. The diagnostic codes showing are P0299 and P0101. The reduced power happened instantly without any prior warning signs. No modifications or tuning have been done to the car, and everything is still stock. The engine runs smoothly with no unusual sounds or vibrations, just significantly less power than normal.

Thanks for sharing your experience. My car has been serviced regularly with the last maintenance at 25000 KM. The dashboard light appeared suddenly while driving on the highway. The diagnostic codes showing are P0299 and P0101. The reduced power happened instantly without any prior warning signs. No modifications or tuning have been done to the car, and everything is still stock. The engine runs smoothly with no unusual sounds or vibrations, just significantly less power than normal.

Based on those specific fault codes and symptoms, your issue seems different from my tuning-related problem. P0299 typically indicates turbocharger underboost, while P0101 points to a mass airflow sensor issue. These car diagnostic codes appearing together suggest an air intake system problem. After seeing similar issues in my Q8, I learned these symptoms often stem from: A clogged air filter, Leaks in the intercooler or boost pipes, Faulty mass airflow sensor, Wastegate actuator problems The car computer triggering both codes simultaneously makes me think your mass airflow sensor might be malfunctioning, affecting the turbo boost control. When this happened on mine, the engine issue was resolved by replacing the mass airflow sensor and cleaning the air intake system. The repair took about 2 hours and cost 320 Euro including parts and labor. A scan tool check after the fix confirmed all systems were working properly again. Quick tip: Before taking it to a workshop, check for any visible boost pipe disconnections or loose clamps around the turbo system. These simple issues can trigger the same fault codes.

Based on those specific fault codes and symptoms, your issue seems different from my tuning-related problem. P0299 typically indicates turbocharger underboost, while P0101 points to a mass airflow sensor issue. These car diagnostic codes appearing together suggest an air intake system problem. After seeing similar issues in my Q8, I learned these symptoms often stem from: A clogged air filter, Leaks in the intercooler or boost pipes, Faulty mass airflow sensor, Wastegate actuator problems The car computer triggering both codes simultaneously makes me think your mass airflow sensor might be malfunctioning, affecting the turbo boost control. When this happened on mine, the engine issue was resolved by replacing the mass airflow sensor and cleaning the air intake system. The repair took about 2 hours and cost 320 Euro including parts and labor. A scan tool check after the fix confirmed all systems were working properly again. Quick tip: Before taking it to a workshop, check for any visible boost pipe disconnections or loose clamps around the turbo system. These simple issues can trigger the same fault codes.

Thanks for the detailed explanation. Your diagnostic makes sense since I havent had any aftermarket modifications done. I checked under the hood and noticed one of the boost pipes seems slightly loose near the turbo connection. Im going to schedule a workshop visit tomorrow and have them inspect the air intake system, paying special attention to the mass airflow sensor and turbo components. The engine issue started right after hitting some rough road patches, which might explain the loose boost pipe. Hopefully its just that simple fix and not a more expensive repair. The car diagnostic codes match exactly what you described, so Im feeling more confident about the potential fix now. Will let you know if replacing the mass airflow sensor and checking the boost pipes resolves the dashboard light and power issues. Really appreciate the suggested 320 Euro repair cost estimate, helps set expectations for the workshop visit.

Thanks for the detailed explanation. Your diagnostic makes sense since I havent had any aftermarket modifications done. I checked under the hood and noticed one of the boost pipes seems slightly loose near the turbo connection. Im going to schedule a workshop visit tomorrow and have them inspect the air intake system, paying special attention to the mass airflow sensor and turbo components. The engine issue started right after hitting some rough road patches, which might explain the loose boost pipe. Hopefully its just that simple fix and not a more expensive repair. The car diagnostic codes match exactly what you described, so Im feeling more confident about the potential fix now. Will let you know if replacing the mass airflow sensor and checking the boost pipes resolves the dashboard light and power issues. Really appreciate the suggested 320 Euro repair cost estimate, helps set expectations for the workshop visit.