1996 Chevy S-10 Small Sphere Under Hood

Shakes or Wobbles problem
1996 Chevy S-10 4 cyl Front Wheel Drive Automatic

Hi, there's a plastic sphere attached to the underside of my S-10 hood, and it has a hose running to the throttle and a wire running behind the firewall, can you tell me what this thing is and if I need it? It's making a ruckus!