Because the camshaft sensor is not in one set place. In the instructions it says to leave the upper timing cover loose until the valve cover is tighten down. With new seals it might not squash down to where factory was so that sets the camshaft sensor in a different place. All the codes went away when I used a pin the size of the hole to time the camshaft sensor wheel through the camshaft upper cover guide. I moved it less than 1/4 inch down from the hole. Running perfect so far.

__________________
2018 BMW X5 Xdrive 50i (M Package)
2002 BMW X5 4.4i /w Sports Package (Sold)
2001 Dodge Ram 1500 Laramie 4x4
2003 Jeep Liberty Limited 2x4