Rough Idle and High Fuel Use Points to TT Throttle Issue

Had similar symptoms with my 2016 Audi S3. The rough engine idle and starting issues pointed to a faulty throttle body assembly. After thorough diagnosis, it turned out the throttle control valve was failing to maintain proper air-fuel mixture. The initial throttle cleaning helped temporarily, but the issues returned within weeks. The complete electronic throttle body needed replacement as the internal sensors were malfunctioning. This was a serious repair since the throttle body is crucial for engine performance and fuel delivery. The car needed programming after installation to sync with the engine control module. Post-repair, the engine idle smoothed out completely, cold starts became normal again, and fuel consumption returned to standard levels. Key signs it was the throttle: check engine light showed throttle position sensor codes, noticeable delay in throttle response, and engine would occasionally stall at stops. Worth checking the electrical connections and throttle body wiring before full replacement. The repair resolved all symptoms and prevented potential damage to other engine components. Regular throttle cleaning might have prevented the complete failure if caught earlier.

Thanks for sharing that experience. My S3 had those exact issues last summer. Wondering how much you ended up paying for the throttle body replacement and programming? Also, have you noticed any air intake or engine idle problems since the fix? Mine cost about 850 Euro total including parts and labor, but prices seem to vary quite a bit. The car throttle response is way better now, though I did have to get the air filter changed a few months after.

After seeing a certified mechanic, the throttle valve defect was fully resolved. The final cost came to 205 Euro for fixing the defective accelerator pedal module, which was quite reasonable compared to your repair. The engine throttle response has been perfect since the fix, no more rough idling or starting problems. Fuel efficiency returned to normal levels immediately after the repair. The control valve is working exactly as it should, and the throttle position sensors are now properly calibrated. Unlike your case, I havent needed any additional air filter work. The regular maintenance schedule seems to be keeping everything running smoothly. Its been about 8 months since the repair, and the car still performs flawlessly with consistent fuel consumption and smooth idle. When checking the repair bill, make sure the throttle position sensor calibration is included in the service. This critical step ensures optimal performance and prevents future issues.

Glad I asked here before jumping into repairs. After reading the responses, I took my TT to a new mechanic last week. The throttle cleaning and control valve adjustment only cost 180 Euro, way less than expected. Turns out the air intake system just needed a thorough cleaning, there was significant carbon buildup affecting the throttle valve operation. The mechanic showed me the before and after pictures of the throttle body, and the difference was striking. The repair took about 2 hours, and the results were immediate. Engine idle is smooth now, cold starts are perfect, and fuel efficiency is back to normal. They also checked the throttle position sensors while doing the work, which were actually fine. No more rough running or starting problems since the fix. Really relieved it wasnt a major issue requiring full replacement. Planning to add regular throttle cleaning to my maintenance schedule to prevent future problems.