BMW M3 Engine Struggles: Is Your MAP Sensor to Blame?

Hey there! I had very similar issues with my 2015 BMW M4 last year. The symptoms you described match exactly what I experienced, poor performance, high fuel consumption, and that annoying check engine light. Turned out I had a significant vacuum leak in the intake system. The rubber gaskets had deteriorated, and there was a crack in one of the vacuum lines. It was actually pretty serious because the engine was running lean, which could've caused more damage if left unchecked. The manifold pressure sensor could be the culprit, but in my experience, it's worth checking the vacuum system first. My mechanic did a smoke test which revealed multiple leaks. The fix involved replacing several gaskets and vacuum lines. It wasn't a quick fix, but the car ran like new afterward. Based on your mileage, I'd definitely get this checked soon. These symptoms won't fix themselves and could lead to bigger issues if ignored.

Thanks for sharing your experience! That vacuum leak diagnosis is spot-on with what happened to me too. Yeah, got it fixed last month and it's running sweet now. By the way, mind if I ask what the damage was to your wallet? And has everything been smooth sailing since the repair? Just wanna know if I should keep an eye out for anything else popping up with these vacuum lines.

Hey again! Glad to hear you got yours sorted too! Yeah, in my case, I went to see the mechanic and they diagnosed both problems, had a faulty manifold pressure sensor AND a nasty vacuum leak. Total bill came to 235 € for both fixes. Not too bad considering the peace of mind it brought! Since getting it fixed, my M4's been running like a dream, way better throttle response and back to its normal fuel consumption. The engine's purring like it should now. Honestly, such a relief getting that sorted! One thing I learned though, these vacuum lines can be sneaky. Even though mine's fixed, I still pop the hood every now and then just to visually check the lines and listen for any unusual sounds. It's worth keeping tabs on them, you know? But honestly, once they're properly fixed, they usually stay that way for a good while. Your M3 should be golden now, but like any performance car, just keep your ears open for any weird noises. These beemers tell you when they're unhappy!

Thanks for the detailed follow-up! You know, my story turned out pretty similar actually. Took it to a new mechanic last week and they did a thorough inspection. Found both a vacuum leak and a worn-out sensor, talk about double trouble! Bill came to a bit more than yours, around 300, but honestly worth every penny. Funny thing is, the mechanic I found was actually super honest. He showed me the old parts and explained everything, way better than my previous experiences. Car's running like a champ now, that sluggish feeling is completely gone and it's back to its old self. Fuel consumption's back to normal too. Really appreciate everyone's input here. Think I've found my new go-to mechanic too, such a relief after that last disappointing experience. Definitely keeping an eye on those vacuum lines from now on though, don't want to get caught out again!