Throttle body question...
While running a new line for a boost gauge, i noticed something a little concerning. I took off the top plastic cover, over the throttle body, and found a port that had no hose. I have never noticed it before, so don't know if it ever had anything. Any ideas?

2001 Tahoe 4x4 5.3l, ?Supercharger?, Volant Intake, Gibson Cat-back, Gibson Headers, Tuned PCM, Fabtech 6" lift, 35x12.50, 20" Black KMC Rockstar's