Crafter Diesel Power Loss Points to Faulty MAP Sensor

Had similar symptoms on a 2020 Transporter TDI last month. The MAP sensor failure caused significant power loss and poor fuel consumption. When the manifold pressure readings are off, the engine management system cant optimize fuel injection properly. After testing the vacuum lines leading to the intake manifold, discovered a major vacuum leak near the MAP sensor connection. The automotive sensor itself was functioning, but the leak was causing incorrect pressure readings. Required replacement of the cracked vacuum line and reseating the MAP sensor with new seals. This is typically a serious issue that needs prompt attention since incorrect manifold pressure readings can lead to long-term engine damage. Running rich fuel mixtures due to faulty sensor data will eventually harm the catalytic converter and EGR system. The symptoms match classic MAP sensor or vacuum line problems: power loss, poor economy, and hesitation under load. Would recommend getting the intake manifold pressure system properly diagnosed with a scan tool to verify if its the sensor or surrounding components before replacing parts. Many times vacuum leaks near the MAP sensor create similar symptoms but cost less to fix than full sensor replacement. Worth having the entire intake system pressure tested first.

Thanks for sharing your experience. The idle issue on my Crafter is similar. Engine performance definitely took a hit and fuel consumption got worse. Good point about checking vacuum lines, I will have that tested before spending money on a new MAP sensor. A mentioned his intake manifold sensor issues ended up being much cheaper to fix than expected. Mind sharing what your total repair cost was? Also curious if youve had any other sensor-related problems since getting it fixed? Was thinking about doing some preventive maintenance while its in the shop.

Just a follow-up on my earlier post, got everything sorted at the mechanic for much less than the initial 400€ quote. They found a substantial vacuum leak in the intake manifold system, which was causing the MAP sensor to send incorrect readings to the engine computer. The total repair came to 235€ for fixing the vacuum leakage, which restored proper manifold pressure sensor operation. Engine performance returned to normal immediately after the repair. The automotive sensor itself was actually working fine, it was just getting false pressure readings from the leak. Since fixing the manifold sensor system 3 weeks ago, fuel economy is back to normal and no other sensor issues have emerged. The engine runs smooth again, especially during acceleration. Would definitely recommend having the intake system pressure tested if youre seeing similar symptoms, could save you money versus replacing parts unnecessarily. For preventive maintenance, having them check all vacuum lines and connections while they have the intake manifold area opened up makes sense. Much easier to address any developing issues while they already have access.

Thanks everyone for the helpful replies. Took my Crafter to a different mechanic who properly diagnosed the issue. Just like others mentioned, it wasnt the MAP sensor itself but a cracked vacuum line causing false pressure sensor readings. Total repair bill came to 180€, way better than the 400€ quote for sensor replacement. They pressure tested the entire intake manifold system and found the leak right away. Also had them check other vacuum lines while they were at it. The car runs perfectly now. Power is back to normal and fuel economy improved significantly. Acceleration is smooth again without any hesitation. Really glad I got a second opinion instead of blindly replacing the automotive sensor. Lesson learned, always get the intake system properly tested before swapping out expensive parts. Having a thorough diagnostic saved me both time and money in the end.