Can't tell for certain but that looks like mine on my 2003 XK8. I took out a bad sensor last weekend and was checking and cleaning the plug hoping it was just dirty. No such luck. It is a bit of a bear to seat fully back in the sensor socket in that you really have to compress it to make sure the tab engages the stud on the side of the sensor.

I was looking for a replacement sensor at the salvage yard but the inboard sensors on the XK8 are "straight" sockets as opposed to the 90 degree "bent" ones on the outer corners. All the XJ and S-Types that I checked appear to use the "bent" style all the way across but the connectors/plugs seemed to be the same to me. I didn't examine them that closely though since I wanted the straight style and I couldn't find any. I would suggest trying a salvage yard. They wanted $8 for a sensor and list a "wiring pigtail" (plug) for $3.77.

Luck!