Don't know specifically, but at the very least do this
Get under the car (with it on jackstands, NOT the jack. safety first)
check out the steering linkages and other parts, make sure the suspension looks firm, and try to move the wheels side to side/up down. The wheels should be firm and not wobbily.
Make sure the sway bar is tight in its mountings. Make sure the struts are firm in place and not moving. Try real hard to move all the aforementined parts, they should not move or dislocate by human force.
What you are doing is the safety checks. That way you do not have to worry about something falling apart on the road...
1999 LeSabre, 3800 series II engine.