What is this vacuum hose? Normal idle when disconnected...

2000 Taco 3.4l V6 with a high idle issue.

When the circled hose is disconnected, it goes back to normal idle (circa 750-900RPM), but when connected it goes to 1200RPM. The vacuum diagram posted below doesn't really help as it doesn't make sense to me. If anyone can help in identifying this hose, or better yet, why it would idle normally when it's disconnected, I'd be incredibly grateful! Thanks bunches for reading this!

 

Welcome to TacomaWorld
With hose off unmetered air creates a lean A/F ratio that sensors cant compensate.
Is Check engine light on ?
AT or MT ?

 

Thanks for the welcome! Sorry for not being specific: MT, no CEL. I tried finding out better diagrams for truck or other people that had the issue, but no luck. Certainly correct me if I'm wrong, but are you suggesting it's possibly a faulty sensor as to why it would idle normally with that hose disconnected? If so, which?

 

Clean the throttle body and MAF.
Plug the hose back in after.
Not suggesting bad sensor just unmetered intake air through disconnected hose.

 

Gotcha gotcha. MAF is clean but I'll look into the throttle body. Thanks!! Just curious, do you know the name of this hose by chance/where it goes? Tried to follow it but it gets all jumbled and apparently dives deep. :/

 

The hose you have circled goes from the intake boot to throttle plenum.
I don't see it going deep or getting all jumbled.
If you start using terms like wanky, cattywampus or discombobulated im outta here

 

Haha fair enough; never said I was an automotive wizard! Honestly, I looked at it when it was -36F here...so my patience trying to trace everything and figure out if something was blocked or whatnot, was a bit slim, especially since I literally have to crawl into the hood to find things (short life!). Thanks for the quick responses and light-hearted humor. I'll try to be more precise with my wording.

 

@2000AKtaco
The hose diagram is for EVAP and EGR vacuum hoses. I will try to find an Intake diagram from the Air box to the Throttle body and post it.
Nite nite for now
Stay warm and dry