S4 MAP Sensor Symptoms Point to Performance Issues

Had similar symptoms on my 2014 S5 with the 3.0T engine. Manifold pressure issues started showing exactly like yours, power loss, check engine light, and poor fuel consumption. The intake manifold sensor reading was inconsistent, causing the ECU to get incorrect air-fuel mixture data. After diagnostic testing, it turned out to be more than just a manifold sensor failure. The problem was a significant vacuum leak at the intake manifold gasket. The automotive sensor was working fine, but the leak was causing false readings. These symptoms often trick people into replacing the MAP sensor unnecessarily. The repair required removing the intake manifold, replacing the gasket seals, and testing the entire vacuum system. Its definitely a serious issue that needs prompt attention, as running the engine with incorrect air-fuel ratios can lead to more expensive problems. Would strongly suggest getting a proper vacuum leak test done before replacing any sensors. When the manifold pressure readings are off, its crucial to verify if its actually a sensor problem or an underlying vacuum leak. The repair took about 4 hours at the shop, and its been running perfectly since then.

Thanks for sharing that experience. Also had the same manifold pressure troubles on my S4, but the car sensor diagnosis showed it was actually just the MAP sensor in my case. Pretty straightforward fix once they pinpointed the issue. Curious what the total repair cost was for your intake manifold work? My pressure sensor replacement was reasonable, but wondering if you ran into any other problems since getting it fixed? Always good to know what to watch out for with these engines.

Thanks for asking about the follow-up. Since getting the vacuum leakage fixed at the intake manifold, the engine performance has been rock solid. The total repair came to 235 Euro, which covered both labor and parts. The faulty manifold pressure sensor readings were definitely caused by that large vacuum leak, rather than a bad sensor itself. The repair shop did a thorough check of all related car sensors while they had it apart, and everything else checked out fine. No other issues have popped up in the months since the fix. The fuel economy is back to normal, and the engine runs smoother than before. Getting proper pressure readings from the automotive sensor system has made a real difference in how the car performs. Worth mentioning that having it properly diagnosed saved money in the long run, replacing sensors without fixing the underlying leak would have been a waste. The car has been trouble-free since addressing the actual problem.

Finally got my car back from the shop today after dealing with those MAP sensor issues. The mechanic I found was much better than my previous one, really knew his stuff about manifold pressure systems and took the time to explain everything. The diagnostic testing confirmed it was just a faulty sensor causing the engine performance problems. Smart move getting it checked properly instead of just throwing parts at it. Bill came to 180 Euro for the new sensor and labor, which seems fair considering the specialist knowledge needed. Car runs like new now. Engine performance is back to normal, fuel economy has improved, and no more check engine light. Pretty relieved it was just a straightforward sensor failure and not something more serious with the manifold or vacuum system. Good lesson in getting proper diagnostics done rather than making assumptions about what needs fixing.