2010 Intermittent Vibration

I searched first, found nothing that matches exactly, so here I go.

My daughter lives 12 hrs away, so I have to work on her car long distance.
Her Prius currently has 178K on it, and the Car has a pronounced intermittent vibration. When visiting her I've driven and ridden in it while it has happened.
It's happened at speed (60-70 mph), and in a parking lot at under 10 mph.
It has been going on for months (maybe 6 months).
After a couple months it finally threw a code (misfire on cyl 4) so we had all the stick coils and plugs replaced...still vibrated.
Having been in it when it vibrated, I took an expensive guess and had her replace both front axles (and the output shaft seals).
It still vibrates.

Since it's intermittent, it's hard to give to a shop for diagnosis.
Also when it vibrates it's very apparent.
Could it be something in the hybrid drive? Are there any universal joints in the system besides the axles?

I'd appreciate any ideas.
Thanks in advance

 

Did I put this in the wrong area?

 

Eventually it turned on a CE light.
It was missing on 1 or more cylinders. Replaced all the coils and plugs and it ran well for 18 months or so.
The replacement coils were Denso.

So, the update to that story is it started missing again.

Replaced the coils and plugs again(no reasonably priced Denso coils available). Stopped the missing for a few months.
Started the intermittent Missing again.
Code thrown was P0172 for "System too Rich Bank 1". She was advised to replace the injectors. Had them replaced and it stopped missing.
700 miles or so later it starts stumbling/missing again.
Running smoothly for long periods with intermittent stumbling.
That slowly changed to running like garbage most of the time.
It is currently throwing these codes,
P0172 System Too Rich Bank 1
P0300 Random Multiple Cylinder Misfire
P0301 Cylinder 1 Misfire Detected

Does anybody have any experience with this set of codes together?
Any ideas, or things to look at?

Thank you