Does anyone know what this hose is?

[SwedeZ]

I'm trying to get my hand down to reach and unclip the wiring harness of the passenger side upstream o2 sensor (it's faulty) but various hoses are in the way, so I'm trying to create a bit more room so I can unclip the little bugger.



When I took off this hose (red circle in picture below) some kind of liquid came out. Not much. It didn't really smell. Felt watery, not oily. Coolant? I'm not really much of an expert when it comes to cars (except for the usual 101 maintenance stuff like oils, filters, brakes, etc), so I wasn't expecting coolant (or other liquids) near the throttle body.



Did I fudge up by allowing in air? Do I need to bleed anything now? Or do I just reattach the hose on the pipe with no worries once I'm done with replacing the 02 sensor?

Appreciate all the feedback I can get.

[40 to 332]

It's a coolant hose that is used to warm the throttle body. Especially useful in cold climates.