Had the same issue, and you probably need a new mechanic. The faulty oil level sensor is likely completely independent of the steering fluid low issue, which to my mind wouldn't throw any codes at all - it's working properly - alerting you to the fact that your steering fluid was low.

Good luck getting it all sorted. I tried two used steering racks off of wrecks and they BOTH had problems leading me to return them. You may have more luck, but you won't know if they're any good until you get them installed, and you'll be risking all of that labor to find out.

If you want to keep the car I'd just bite the bullet and get a new part, though before you do make double sure the active roll bars aren't leaking - they're all driven using the same hydraulics.

 

I was getting that same error off and on for months. All I had to do was top off the power steering fluid. The error hasn't returned since.

Check your power steering fluid level.