i've owned 3 cadillacs and an aurora wich runs the same engine as cadillac and had the same problem with all 4 vehicles, they all stall at traffic stops. I was told by the dealership mechanic that this is a common problem due to the casing of the sensor becoming brittle by the engine heat.
Car will idle alright and drive good then when i come to a stop the car will cut off. The amazing thing is the dealership charged me 1,500 dollars and said it was fixed , however the car is still shutting off. They said it wasalot of gas in the intake.