TOPIC: What is the function of this port on my throttle body?

Re: 2009 Toyota Camry 2.4

It's not IAC or the brake booster, but it's little hose plugs into it's own little vacuum port on the intake-manifold (bypassing intake-runners). I've searched for while to find out the function of this throttle-body port. I get that it's minuscule and super specific, but if it's part of the engine it's only there to serve 'some' purpose, but nobody seems to know - and I'm not sure how many other makes/models even have this 4th throttle-body. Even Toyota's own diagram and service manual only go as far as naming it "hose"... I've only heard one person who has the same car, on either youtube or toyo-nation forum, refer to it as a 'drain pipe' but what needs to be drained from a throttle-body and at the expense of engine vacuum? (never got a response to that question)

The hose highlighted below is the one in question.

I'm beginning to wonder if it's just a subtle design with malicious intent like the PCV in which case there should be nothing to lose by capping-off both ports (red). Thoughts, ideas, anyone ? Thx!

Interesting question.
is it maybe to vacuum up any condensation from a breather upstream of the throttle plate? is there a reason that the actuator motor might need to be subject to a vacuum (it looks like the port is right on where the motor that moves the butterfly - the gears are under the cover near the electronic connection) ?
Can you take a pic of one of these animals?
Maybe Claudio Cordova has some insight - he's dialled in or connected to foreign car dealerships as I recall

One way to obtain information like this is to call the local dealer's parts counter, or make a visit, and ask for the PDF breakdown of the part.

Two or three times a year I need to do this. They'll even email it to you if you ask real nice!

Ron

I went ahead and capped-off those two ports (in red) and removed the hose (in yellow). There's noticeably more power and it fixed the issue I was having with the engine bucking/stubling (rpm bouncing up and down as if trying to get in gear) during high acceleration.

Here's a photo of the same model TB, upside down of the diagram above.

If I were you, I would check under the cap on the TB weekly for a while to see if anything is collecting, and again in cooler weather. There is a reason the factory put that there, and if it’s for long term reliability of the TB, the engineers decided in favour of that rather than fuel economy/power.

We may all ponder this small mystery while you enjoy the benefits of pulling and capping off this mystery hose, Wes. We may all be thankful that the peak of the emissions vacuum hose jungle syndrome was way back in 1985. Next time in a junkyard, have a look underhood at cars from the late 70's to mid Eighties. Even if the engine is gone, try to find a vacuum hose diagram decal . If you do, marvel at the awesome complexity. Some of these buggers look like a London street map.

I once did extensive work on an '84 Honda CRX. Cool little ride, and it had a 3 bbl. carb. There were many vacuum hoses and vacuum gizmos, and it had this big black box full of vacuum solonoids, with un-decipherable purpose. So as a warning to others, I labeled this thing "Pandora's Box" in multi-colored model paint.

Tracy G