My doughter's 99 Lumina stopped accelerating while

That's normal operation for automatic traction control.

Sounds like the auto throttle is jammed or the throttle pedal is jammed. Try pushing on the gas pedal a few times to see if it frees.

run the fault codes. If it a cable operation then replace the cable.

My APV locked in overdrive and would stall the engine at stops. This van was my daughters and they had junked it because of the cost of repair. I would test the tranny lock up by coasting up to a stop and if I sensed the tranny was locked I would floor the accelerator a couple of times with a quick back off each time. After a dozen or so of these procedures whatever was sticking thje lockup came free and the problem was mixed.

is the ABS light on? Check the crank sensor wiring down the back of the block, it may have melted on the exhaust. It runs in between the firewall and the engine, 2 wires.

yes, and check your cable coming from you pedal and up to throtle

the auto-transmission control linked to accelerator pedal might have changed its position.loosen the screw on the sliding lever,start the engine ,slowly slide the lever and once it started engaging set t/m about 900rpm.

Your problem seems to be the mass air flow meter.Have you ever changed it?

check fluid level, make sure proper fluid is in transmission otherwise take to trans shop to diagnse if level and type is correct(check at idle normal operating temp)

Sounds like the throttle position sensor It is attached to the throttle body up by the intake Go to the part stroe and get one if your not sure what it looks like