I suspect you've fixed this by now, but if not, I'm prepared to resurrect your question from the grave :-)
Personally, given your description of metal on metal grinding and loss of brake pedal pressure I would be chasing a problem in the brake system rather than the steering to start with. It sounds like the only "steering" related symptom at this point is squeeking when you turn the wheel.
I can't say for sure that it's not your steering, but I would check to make sure that all of your brake pads are intact and that the calipers are bolted on tight.
I've seen similar symptoms in the past when people have loose lugnuts on the wheels as well, so checking that those are all torqued on appropriately could be helpful as well.
Also, with the "lean" engine code, you should check to make sure there are no vaccum leaks.