So, I have had this car for 11 years and never had this issue. I tried searching but got nothing.

So, when I corner hard and really load up the suspension, the steering wheel starts to turn back and forth a little almost as if the car was followinf road imperfections, but the car holds its line and grips just fine. I have only noticed this on right turns, but there aren’t as many opportunities for sustained left turns around here this time of year due to winter weather in the mountains. Any ideas?

The car has been aligned recently, made no difference.

Ideas I have based on the car being high mileage:

-worn out tie rods (but the steering feels solid and precise at all other times)

-bad tire? (But grip seems fine)

-hub? (But no other symptoms)

I will double check my tire pressure when I get out of work since it just dawned on me I haven’t checked it in a month or two.

 

Same make and age tires, on left and right? Same pressure? Here's a link on possible EPS problems.

Steering wheel shakes

 

Want to say torque sensor is the culprit, they tend to act up more in the cold than when it's warm for some reason. There's threads here on how to clean them. Basically you have to remove it, take off the tamper proof torx bits and clean and regrease the strain gauge. The beige thing with the spring has to move smoothly, when it's cold the dried up grease causes the beige thing to bind over it's sliding motion giving wonky readings to the torque sensor POT. It's a bit tricky to remove, and reinstall, two bolts holding the coupler, two bolts holding the sensor, and an electrical connection. Billman has a good technique for popping the unit back in. Putting gentle upward pressure on the halfway point of driver side tie rod with a jack compresses the internal rack spring and allows it to pop into place.

 

So I figured it out. Two compounding issues. One is my tire was low. Not gross but just enough to cause some squirm. After inflating it I still had the issue though greatly reduced. Checked the steering rack and 2 of the bolts were slightly loose. Tightened them and issue completely gone.