Carb tubing 1999 IS

[IBE]

 I have a tube coming from a "T" that is between carbs 4&6 that goes to other "T" with a hose that goes to "T" Between carbs 3&5, What connects to the open end of the "T" where the 2 tubes meet? These tubes r for air not Fuel they set at the top of the carb rack. 
Thanks
IBE

[BonS]

The two tubes insert into two holes that are in the rear carburetor brace that runs between carbs #5 & 6. The two tubes are vents and just point downwards after being inserted in their respective holes.