Mercedes E Klasse Hybrid Check Engine Light and Power Loss

That sounds plausible The MAP sensor measures pressure inside the intake manifold A vacuum leak could cause incorrect readings, triggering your symptoms The ECU uses MAP sensor data to calculate air density and determine the correct air/fuel mixture If the sensor is faulty or getting bad readings due to a leak, it will mess up the fuel trim, leading to reduced power and increased fuel consumption Did they check for vacuum leaks using a smoke test or just a visual inspection

Thanks for the quick response They didn't mention a smoke test, just a visual inspection of the intake manifold area Is a smoke test really necessary Could I replace the MAP sensor myself, or is it best left to a professional I'm reasonably handy with tools, but I don't want to mess anything up further

A smoke test is the most reliable way to pinpoint vacuum leaks Visual inspections can miss smaller cracks or hidden leaks As for the sensor replacement, it's usually straightforward However, considering the potential for vacuum leaks and the complexity of a hybrid engine, I advise taking it to a trusted workshop They can properly diagnose the issue, perform a smoke test to confirm and fix any leaks, and then replace the MAP sensor if needed It's better to be certain than to just replace the sensor and still have the problem

You were spot on I took it to a proper workshop, and they did a smoke test There was a small crack in one of the intake manifold hoses They replaced the hose and the MAP pressure sensor, and the car is running like new again The total cost was 235€, which is a bit more than just the sensor, but worth it for the peace of mind Thanks for your help I really appreciate it