The ornamental design for an oxygensensor boss, as shown and described.
FIG. 1 is a top plan view of the first embodiment of oxygen sensor boss according to my design;
FIG. 2 is a bottom plan view thereof;
FIG. 3 is a front elevation view thereof, back elevation view is identical;
FIG. 4 is a right side elevation view thereof, and the left side elevation view is identical;
FIG. 5 is a bottom perspective view thereof;
FIG. 6 is a top perspective view thereof; and,
FIG. 7 is a bottom perspective view of a second embodiment of the design, wherein the only difference to first embodiment being in that a lip added at the bottom.