If it made a whining noise before the steering felt like it went completely out and possibly seen fluid on the ground, on the passenger side near the engine, it's likely you've lost all power steering. It's very common in impalas, typically starts off as your high pressure hose; then, your pump goes out, making a pop noise when it does, due to no fluid in it. Then, your rack and pinion goes bad.(without notice because powersteering is already gone, fluid is already drained out of the hose, or you forget to properly drain the system when replacing a hose or pump) Finally, if you keep driving(because you don't know better or have replaced them so many times you just decide to drive without power assistance) your power steering pully will break completely(because pump had no fluid to grease the bearings) off while going down the rd.(you might not know this happened but your battery light will come on and you should hear pieces of the pully hit the ground under your car) With any 2000+ year impala's having power steering problems, handle them immediately, and it'll save you an arm and leg; and, at very least when bypassing your power-steering, seal the pump off with fluid in it and possibly upgrade to after market metal pully.
