1991 Buick Century stalliing

There's a very good chance it's the "Mass Air Flow Sensor". My daughter has a 95 Buick Century, that's been doing the same thing for a couple of months now. At first it was a rare occurance. Then a VERY, VERY frequent one. You drive your car for 10 to 20 minutes and whenever you stop or come to a idel speed it would die, then start right back up. Check engine light comes on more and more. Eventually it's on as soon as you start your car. I used a "Actron Super AutoScanner CP9145 OBDll code reader", to verify my diagnosis and that's exactly what it was. The Mass Air Flow Sensor". Fortunately, it's a easy part to access and remove since it's right on top of your engine. Mine cost, (with a core charge) $136.00 at Autozone. Good Luck. :-)