Why does your 2001 ford explorer sport track squeal when you step on the gas pedal?

There are several different possibilities, the most common cause is probably a drive belt. They get stretched out over time and can glaze over, making them lose friction on the pulleys which will make a loud squeal. Inspect your drive belts. If they are cracked, shiny in appearance, or lacking tension, try replacing them and see if that fixes the noise.