IACV workings

recently pulled a 2000's toyota 3sgte idle air control valve apart and noticed the throttle body and valve have the provision to simply bypass the throttle body. why does toyota run a separate feed into the IACV? (3 wire BAC type)

what are the down sides of opening up the throttle plate bypass and blocking the separate feed like?

its appealing as it will be more compact and tidier in the engine bay, but i would proffer to know why toyota went to the extra effort?

Thank you

Hello there is no downside to doing this, it is a common mod used

i appreciate the answer Ross, however i am still curious why Toyota goes to the extra expense and trouble to run a hose to the air box etc?

does it have emissions implications?