Faulty Air Sensor Causing TT Engine Issues and Power Loss

I had nearly identical symptoms with my Audi A4 2009 about six months ago. Having some experience with car diagnostics, I first noticed the engine performance issues and check engine light, just like you described. The car sensor readings were totally off, and the temperature reading fluctuations made it clear something was wrong with the air temperature monitoring system. After checking with a diagnostic tool, the intake air temperature sensor showed similar error codes to what you are describing. I took it to a workshop where they confirmed the air sensor was defective. The total repair came to 155 Euro, including parts and labor. They had it fixed within a couple of hours, and the difference in performance was immediately noticeable. Before I can provide more specific advice, could you share: The engine size of your TT, The exact error codes you are seeing, Whether the issues occur more during cold or warm weather, If you notice any specific timing of when the symptoms get worse This information would help determine if your situation matches what I experienced and could point to whether its definitely the intake air temperature sensor or possibly something else.

Thanks for sharing your experience. I have the same symptoms with my TT at 183632KM. Used my diagnostic tool last weekend and pulled code P0113, which points to the air temperature sensor circuit running high. The engine issues worsen noticeably during cold starts, and the temperature reading seems way off compared to actual ambient conditions. I was hesitant about workshop costs, but 155 Euro sounds reasonable if it resolves these problems completely. Did you notice any fuel consumption improvements after the repair? My engine has been using more fuel than usual lately.

Yes, the fuel consumption issue you mentioned matches exactly what I experienced with my A4. After replacing the faulty intake air temperature sensor, I saw around 15% improvement in fuel efficiency. The engine management system relies heavily on accurate temperature readings to optimize the fuel mixture. The P0113 code you pulled is the same one I had, so this further confirms we are dealing with the same issue. Cold start problems are a classic indicator of air temperature sensor malfunction, as the engine control unit needs accurate intake air readings to calculate proper fuel mixture during warm-up. The 183632KM reading suggests this is likely the original sensor, which typically starts failing around this mileage. The workshop cost I mentioned included them cleaning the entire intake air system, which I would recommend since you are already having the work done. This comprehensive service helped ensure optimal performance after the repair. After the fix, besides the fuel economy improvement, I noticed: Smoother idle, More consistent power delivery, No more check engine light, Much more reliable cold starts With identical symptoms and error codes, you can expect similar results. The repair should resolve all the engine issues you are experiencing.

Thanks for the detailed insights about the IAT sensor repair. After comparing your experience with my TT symptoms at 183632KM and the P0113 code, it seems our issues match perfectly. The cold start problems and high temperature readings I am seeing definitely point to the same diagnosis. Good to know about the fuel consumption improvement after your repair. My car has been quite thirsty lately, so a 15% efficiency gain would be significant. The 155 Euro repair cost is much more reasonable than I expected, especially if it includes a full intake system cleaning. I will schedule the repair next week and have them check the entire intake air system while they are working on it. The fact that you saw immediate improvements in cold starts, idle quality, and power delivery is encouraging. Having the temperature sensor replaced at this mileage makes sense since these parts typically need service around this interval. Thanks again for helping me confirm the diagnosis. Will move forward with getting the intake air temperature sensor replaced and hopefully see the same improvements you experienced.