BMW 4 Series Engine Woes: Knock Sensor or Something Else?

Thanks for sharing your experience! That's really helpful as I'm dealing with the exact same symptoms. Mind if I ask how much the repair ended up costing you? Just trying to get a rough idea of what I might be looking at. Also, have you had any other issues pop up since they fixed it? The whole connector and wiring harness thing sounds way better than having to replace the entire sensor.

Thanks so much for all this detailed info! I actually just got back from the mechanic and you won't believe it, my issue was super similar! Took your advice about finding someone who knows BMWs well, and I'm glad I did. The guy knew exactly what to look for. Turns out my knock sensor connection was also the culprit, along with some dirty wiring. Total bill came to about 120 bucks for cleaning and fixing everything. Such a relief, I was worried it'd be something way more expensive! Car's running perfectly now, no more rough idle or sluggish performance. Fuel consumption's back to normal too. Honestly, I feel pretty silly for worrying so much about it. Found myself a reliable mechanic in the process, so that's a bonus. Really appreciate you sharing your experience, helped me avoid getting ripped off for unnecessary repairs!