le sabre

Hey everyone, I've been having issues with my 2003 Buick LeSabre Limited. My car sometimes stalls when I am idling, shifting to reverse or back to drive or park. When idling I can hear and see my RPMs increase and decrease randomly but mostly is normal but will drop low enough to stall...

Put the brakes on quickly driving through a parking lot when someone started backing out. You can imagine the slow speed I was driving and the type of braking I performed. Quick, just once, and then on my way. The warning light for the brakes came on and has stayed on ever since. I have checked...