Smart Forfour Power Loss Points to MAP Sensor Issues

I had nearly identical symptoms with my Smart Fortwo 2007. After dealing with poor engine performance and increased fuel consumption, I took it to a workshop where they diagnosed a large vacuum leak affecting the manifold pressure readings. The mechanics performed a smoke test which revealed the issue wasnt actually the MAP sensor itself, but rather a cracked vacuum line that was causing incorrect pressure sensor readings. They also checked all related car sensors to ensure there werent multiple issues at play. The total repair, including parts and labor, came to 235€. Since the fix, the engine performance returned to normal and the check engine light went off. The fuel consumption also went back to expected levels. From my experience with similar engine performance issues, its important to have a proper diagnosis before replacing parts. Could you share: Current mileage, When the symptoms first appeared, Any other warning lights besides check engine, Whether the issues occur more during cold starts or when the engine is warm This information would help determine if your situation matches what I experienced with the vacuum leak or if theres something else going on with your manifold pressure system.

Thanks for the detailed info about vacuum leaks. Just had my last service at 168721 KM and the mechanic used advanced diagnostic tools to check all automotive sensor systems. In my case, it turned out to be the MAP sensor after all. A full sensor analysis revealed erratic manifold pressure readings. The replacement part cost 180€ plus labor. All engine performance issues cleared up immediately after the repair, no more power loss or excessive fuel consumption. The electronic diagnostic report confirmed the manifold sensor was the root cause, with no vacuum leaks present. This experience shows how similar symptoms can have different underlying causes, even when dealing with car sensors in the same system. A proper diagnosis is essential for targeting the actual fault.

Thanks for sharing your sensor replacement experience. It reinforces the importance of proper diagnostic testing since vacuum leaks and faulty manifold pressure sensors can produce identical symptoms. In my Smart Fortwo, the smoke test proved crucial in revealing the vacuum leak. But your case demonstrates how a bad MAP sensor itself can trigger the same issues. The automotive sensor analysis your mechanic performed was the right approach to pinpoint the exact problem. Your repair cost of 180€ plus labor seems reasonable for a manifold sensor replacement. My vacuum line repair was slightly more at 235€ total, though costs can vary. The key takeaway from both our experiences is that pressure sensor issues, whether from the component itself or related vacuum problems, need proper diagnosis rather than assumptions. For others reading who face similar engine performance problems: make sure your mechanic does a complete sensor analysis before replacing parts. Modern car sensors are interconnected, so isolating the actual fault prevents unnecessary repairs.

Thanks everyone for the great discussion about manifold sensors. It really helped confirm my initial suspicions about the MAP sensor being the culprit in my Smart Forfour. Getting that proper diagnosis using the right testing equipment made all the difference. Good point about checking for vacuum leaks too, glad my mechanic did a thorough intake manifold inspection to rule that out. The pressure sensor readings were clearly showing the MAP sensor itself was failing rather than having vacuum issues. The 180€ plus labor I paid for the replacement feels fair given how it completely resolved my performance problems. No more sluggish acceleration or high fuel consumption. The automotive sensor diagnostic process may have cost a bit extra but it saved money in the long run by identifying the exact problem. Really valuable to hear about different experiences with similar symptoms. Shows why proper testing of car sensors is so important rather than just swapping parts and hoping for the best. My engine is running like new again thanks to the accurate diagnosis and repair.