SQ5 Power Loss Points to Faulty MAP Sensor

Had similar symptoms on my S4 (2013) last winter. After proper diagnosis, it turned out to be a vacuum leak causing the MAP sensor to send incorrect readings to the ECU. The intake manifold showed signs of wear where it connects to the pressure sensor. Main symptoms matched yours: Increased fuel consumption, Power loss during acceleration, Check engine light, Sluggish response The MAP sensor itself was working fine, but the vacuum leak meant it received incorrect pressure readings. The real fix required replacing the intake manifold gaskets and checking all vacuum lines. This was a serious issue that needed immediate attention, as continued driving could have led to further engine performance problems and potential damage. A specialized shop with proper diagnostic tools is crucial for this type of issue. Regular mechanics often misdiagnose vacuum leaks as direct sensor failures. Make sure they perform a smoke test to properly identify any leaks in the system before replacing parts. The repair process involved: Complete vacuum system diagnostics, Intake manifold removal and inspection, Replacement of worn gaskets and seals, MAP sensor validation testing, Full system pressure test Car ran like new afterward with normal fuel consumption and proper throttle response.

Thanks for sharing your experience. I actually ran into this exact same issue with my SQ5 a few months ago. The symptoms match perfectly and the vacuum leak diagnosis makes total sense. I am curious though, how much did the entire repair cost you? My mechanic is giving me different quotes and I want to compare. Also, have you noticed any other issues popping up since the repair was done? The manifold pressure readings on my car still seem a bit off even after initial fixes, so I want to make sure I catch any potential related problems early. Would really appreciate any insights about the long-term reliability after your sensor replacement and manifold work. I want to be certain everything is fixed properly this time around.

Thank you for asking about the follow-up. The repair costs came to 235 Euro total to fix the large vacuum leakage that was affecting the manifold pressure sensor readings. The automotive sensor system now works flawlessly, no additional issues have emerged in the months since the repair. The engine performance returned to normal immediately after fixing the faulty manifold pressure sensor and sealing the vacuum leak. Fuel consumption is back to factory specifications and acceleration response is crisp again. Based on my experience, once the intake manifold components are properly repaired and all vacuum lines are correctly sealed, the fix tends to be permanent. The car sensors now show consistent readings across all driving conditions. Some tips for long-term reliability: Regular checks of intake manifold gaskets prevent future leaks, Monitor engine performance through the OBD system, Pay attention to any changes in fuel consumption, Schedule preventive inspections of the vacuum system The investment in proper diagnosis and repair was worth it for reliable operation. No warning lights or performance issues have returned since the fix.

I finally got this resolved and wanted to share my experience. Took the car to a different shop that specializes in car sensors and diagnostic work. Their thorough testing showed it was indeed a vacuum leak affecting the manifold pressure readings, just as suggested. The total repair came to 280 Euro, which included: Complete vacuum system inspection, New gaskets and seals, Labor for manifold removal, Pressure sensor calibration, System testing After driving for several weeks now, engine performance is completely back to normal. The car sensors are showing proper readings, fuel consumption dropped back to usual levels, and acceleration is smooth again. The engine control unit shows no error codes. What really made the difference was finding a shop with proper diagnostic equipment who understood how automotive sensor systems work together. They spotted the actual problem instead of just replacing parts hoping to fix it. For anyone facing similar issues, get a proper diagnosis with smoke testing before replacing expensive parts. A failing manifold pressure sensor might not always be the root cause.