Low Pressure or High Pressure?
I saw your post and I viewed a few other posts and now I'm confused. I thought the low pressure sensor was right next to the air box hood intake hole. I need to replace my sensor and the fuel control module but I want to get the correct one. What was weird was that I took the part number off the existing sensor near the air box (PN 7547883-04) and I tried to find a replacement and it came up as an air conditioning sensor. I wonder if they are interchangeable or if someone installed the wrong part. My car has bucking issues when its cold and the idle fluctuates. It also pings at part throttle off idle which is annoying. The part I purchased is 13 53 7 614 317 so I hope it works.
Are you sure the sensor you replaced under the plenum wasn't something else? I'm an experienced mechanic but I'm new to working on the E90 M3.
There is a serious lack of helpful technical information on these cars.