There is no pick up ring in my e53 I looked in the hole and didn't see one. I previously sprayed brake cleaner in the hole and spun the axle.
As previously stated the OEM is OVI/Siemens. I put in a Febi brand sensor from Pelican and wonder if that what's causing the gap error? Before reading this I ordered a OEM one and will put it in tomorrow, weather permitting and will keep the forum up to date for peoples future reference.