1999 Buick Park Avenue car shuts down while driving

What are you missing spark or fuel?

Spark

Check and test the coils and make sure its getting power

Does it do it after it is warmed up? Will it cut out while idling also? If it does, do a simple test. The Air Flow Meter, or Mass Air Flow sensor (black, thin, flat device) is on the top of the aluminum throttle body near the large rubber flex hose that connects the air filter box to the throttle body (just downstream to the pass. side) and it is held in place with 2 torx 20 security screws (they have a protrusion in the middle of it so you can't take the screws out with a regular #20 torx screwdriver) anyway with the car warmed up and idling take a screw driver or use your fingers to tap on the top of it and see if the engine will stumble or raise or lower the rpm, just by tapping on it. If it does then your AFM or MAF....whatever they call it.... is bad. It should not change the rpm by just tapping on it. You can look at my post and read what I did to mine here http://www.2carpros.com/forum/1999-buick-park-avenue-engine-cuting-out-amp-stalling-whe-vt358111.html