I have a leaky valve stem on my right front tire. My tire sensor is working properly. Can someone tell me if the valve stem is connected or part of the sensor? Many thanks for any info.

 

The majority of the time the stem is part of the sensor. Some older sensors were mounted to the center of the wheel rim.
If it is leaking out the opening where the air goes in, a simple valve cap/tool can tighten the core if it is loose, otherwise it may need to be replaced.
Use only plastic valve caps to prevent corrosion from dissimilar metals.