Your dome lights on your 2001 Pontiac Firebird isn't working when doors open or switch on fuse and bulbs are good and the map lights work?
If your map lights come on when the door is opened then the
problem lies with only the dome light.
check the bulb and test the wires for voltage and ground.
there may just be a short in the ground.
that's the most common problem with interior lighting.
In my opinion.
hope this can help.