Audi S3 Power Loss & Limp Mode: Throttle Sensor Alert

Had a similar issue with my 2014 Audi S4. As someone with some mechanical experience doing basic maintenance, I understand your concern about the throttle sensor symptoms. The throttle body assembly including the throttle sensor started acting up, causing similar problems, rough engine idling, limp mode activation, and power loss. The entire throttle control module needed replacement. The issues began intermittently but became more frequent. At first, the engine would occasionally stumble during acceleration, then progressed to constant check engine lights and significant power reduction. Got it fixed at a workshop specializing in VAG engines. The total repair came to 265 Euro, which covered both parts and labor. The repair involved replacing the electronic throttle control module and recalibrating the new unit to work with the engine management system. This sounds very similar to your situation, especially the symptoms you describe with the air intake and throttle response. Could you share: Are there any other warning lights besides the check engine light? Does the issue occur more frequently when the engine is cold or warm? Have you noticed any changes in fuel consumption? Did you scan for error codes? This information would help determine if your issue matches what I experienced with my throttle sensor replacement.

Last service was at 119500 KM, just a few weeks ago. Thanks for the detailed response. Just had it scanned and got error code P2101. The issue definitely occurs more when the engine is cold and takes about 10 minutes of driving to somewhat stabilize. Fuel efficiency has dropped significantly, getting about 20% worse mileage than usual. The mechanic quoted 450 Euro for the throttle sensor replacement including labor. Your experience gives me some confidence this might actually fix the issue, though the price is quite a bit higher than what you paid. The rough engine idling is really starting to worry me, so I might just go ahead with the repair rather than risk further damage to the air flow system. No other warning lights showing up currently. Will get it fixed next week and update the thread with results.

Thanks for the update on your S3. My S4 showed the same P2101 code which confirmed the electronic throttle control issue. The cold start symptoms you describe match exactly what I experienced, the engine response delay and rough idling were definitely worse until everything warmed up. The 450 Euro quote seems on the higher end compared to what I paid, but prices can vary. If theyve included a full throttle body cleaning and calibration in that price, it could be worth it. The important thing is getting the air flow system working correctly again to prevent any cascade of issues. After my repair, the improvement was immediate, smooth idle, proper throttle response, and no more limp mode activations. Fuel economy returned to normal within about 2 tanks of fuel as the engine management system adapted to the new throttle body. One tip: after the repair, try to do some varied driving (different speeds, gentle acceleration) to help the system learn and adjust properly. Looking forward to hearing how the repair works out for you.

Great insight about the P2101 code matching your experience. The cold start behavior definitely seems to point toward the throttle sensor being the culprit. I noticed the same pattern with my S3, really rough performance for those first 10 minutes of driving. The price difference is a bit concerning, but after seeing how my fuel efficiency has dropped and experiencing these constant limp mode issues, I think I will proceed with the 450 Euro repair. The risk of causing more damage to the air flow system by waiting isnt worth the potential savings. Already scheduled the work for next Tuesday. Will drive it carefully until then to avoid any additional stress on the engine. Really hoping to see the same immediate improvements you mentioned, especially with the rough idling and throttle response. The 20% hit on fuel efficiency is getting expensive. Will definitely follow your advice about varied driving after the repair to help with the adaptation period. Planning to post back here once its fixed to confirm if it resolved all the symptoms. Thanks for sharing your experience, its been really helpful in deciding how to proceed.