i have a 2000 honda civic ex and my intake has 3 holes. one for the iat sensor, the pcv system. but i dont know what the last one is for, a hose is connected to it. what is it?

 

 

WTF my engine doesnt have that....

How could that negatively impact performance ron?

 

The importance of the FIA system is a bit of a mystery to me because I haven't yet read a thread where its malfunction causes a problem. Based on information in the diagram, I presume the FIA system functions to raise the idle speed when the engine is cold, which seems somewhat redundant with the IACV. Maybe somebody else here knows more about the FIA system.