I've tried everything I can think of, but no matter what I do I cannot get the built in audio metronome to be included on the exported wav file. My Audio track (an imported wav) & my midi trak (drum beat) get exported fine to the output wav file, but the metronome will not. It plays fine during project playback, but the exported wav lacks the metronome sound. What am I doing wrong, or does Sonar X2 Essential have this ability?

Metronome is designed not to be exported. Many would not want this to be exported, but only for recording.

However, you can setup a cowbell (via TTS vsti or others) loop easily, to be exported.

Yes if you want to include a click track or metronome, created it inside the project...then export.  Very simple thing to do.  .  The metronome is not exportable.  

Lately I have been using the metronome as an purc source for a bunch of newer pieces.  With echos, reverb,.....

Haven't gotten to the end mix phase. Yet. 

But I have never used export. I always use bounce to tracks.

I will test to know if bounce to tracks works. Maybe have to use real time.

If not I will route through the EMU patch mix. And back to a track. Fur shur get everything that way.