1994 Buick Park Avenue

Engine Performance problem
1994 Buick Park Avenue 6 cyl Two Wheel Drive Automatic 200, 00 miles

My 1994 Buick Park Avenue is about to drive me nuts! As long as I am driving on the open highway, it keeps going. It stutters from time to time, but I can live with that. But the minute I hit start and stop traffic, after a few redlights, it will start sputtering, then kill out. We've replaced the fuel pump, cleaned the injectors, and replace the wiring harness that goes to the mass air flow sensor. We are about to replace the mass air flow sensor. But it costs $130+ and I want to make sure that it can cause the problems I have described, or if we need to look elsewhere. Please help! I am desperate. I'm almost out of money to keep putting in this car.
January 12, 2010.

Check and test the following below: Oygen Sensor
Catalytic Converter
Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)

Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include: Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Wet plug wires
Cap and Rotor

Note: If it doesn't apply, disregard.

Jan 12, 2010.
Thank you for such a rapid response. Will try what you have suggested. Thanks again!

Jan 12, 2010.