Audi S3 Manifold Sensor Killing Performance and MPG

Had similar symptoms with my 2010 Audi S4. The MAP sensor failure caused rough idling and significant power loss. During diagnostics, vacuum leaks were discovered in multiple locations, particularly around the intake manifold gasket. The manifold pressure sensor was sending incorrect readings to the ECU, causing improper fuel mixture. This explained both the performance drop and increased fuel consumption. The repair involved replacing the MAP sensor and addressing all vacuum leaks, definitely a serious issue that needed immediate attention to prevent further engine damage. In my case, both the manifold sensor and intake gasket required replacement. The pressure sensor itself is a straightforward swap, but vacuum leaks often hide deeper issues. The garage found deteriorated vacuum lines and a cracked PCV valve during inspection. For accurate diagnosis, ask the shop to perform a smoke test to identify all vacuum leaks. A proper manifold pressure test should also be done before replacing the MAP sensor. These tests help avoid unnecessary parts replacement and ensure all related issues are addressed at once. Leaving this unrepaired risks damaging other engine components due to incorrect air-fuel ratios. Consider getting a second opinion if unsure about the diagnostic results.

Thanks for sharing your experience. I had nearly the same problem with my Audi S3 a few months back. Just wondering, how much did you end up paying for the complete repair? After fixing the manifold sensor and vacuum leaks, have you noticed any other issues popping up? The automotive sensor prices seem to vary quite a bit and I want to make sure I budget correctly for this repair.

Thanks for asking about the costs. After getting the work done, I paid 235 Euro to fix the large vacuum leakage that was causing the manifold pressure sensor malfunction. The repair has completely resolved the issues, no more engine performance problems or excessive fuel consumption. The MAP sensor replacement was actually straightforward once the main vacuum leak was identified and fixed. Engine response is now much smoother and the check engine light has stayed off. The manifold pressure readings are now accurate, which has restored proper fuel mixture and normal performance. For anyone facing similar symptoms, getting a proper diagnosis is crucial. In my case, simply replacing the sensor without addressing the vacuum leak would have been a waste of money since the underlying issue would have persisted. No additional problems have surfaced in the months since the repair. The engine is running at peak efficiency again, proving that addressing both the faulty pressure sensor and vacuum leak was the right approach.

Wanted to update everyone on how this turned out. Finally got my S3 fixed last week and the experience was actually better than expected. Found a specialized shop that really knew their stuff about engine performance issues. They ran a complete diagnostic and found the manifold sensor was indeed bad, but also discovered a small vacuum leak that was making things worse. The mechanic showed me exactly where the problems were and explained why the sensor failure was affecting my fuel consumption. Total bill came to 280 Euro including labor, which was fair considering they replaced the MAP sensor and fixed the vacuum leak. The whole job took about 3 hours. Big difference in how the car runs now, much smoother idle, better acceleration, and fuel consumption is back to normal. Really glad I asked here first because it helped me understand what to expect at the shop. The engine performance is completely restored and no check engine light since the repair. Definitely worth getting it done right the first time.