I have a 2002 Mitsubishi Galant and it blows black smoke when I push the accelerator. Why is that?

Black smoke is unburned gasoline. Possibly your o2 sensor has failed and not sending a signal to the ECU, or the wrong signal, that is what controls the fuel/air ratio and your car is running very rich

Another possible cause is a bad fuel regulator. The increased fuel pressure squirts extra fuel into the cylinders.

Did this start suddenly or has it been happening a long time? If it has been a long while, it could be worn piston rings and that could be burning oil.

Yeah,right on. he (she)? didn't say miles on car.

dirty air filter might cause this-

The mileage is 152,000

for a mitsubishi? the Zero was only supposed to last long enough to complete it's mission. has your mitsubishi completed it's mission?