ck123

so yesterday i had time to an oil change, so i drive it around the block a few times to get oil to temperature. So i begin jacking up the car and notice a small puddle of water....ok so i go under my car and see a black tube near the cat that is letting this water leak out. Just wondering what this is for since i can tell this was purposely done by acura.

my guess is to let the exhaust moisture out to prevent internal rusting of the exhaust?

what is it for

miner

Most likely the AC drain tube. It drains the water that builds up in the AC lines/condensing area. If it ever gets blocked then water will end up in the interior footwell.

DuckDodgers

Quick check of the Service manual shows that it is, like miner suggests, most likely the A/C evaporator core drain hose. While the diagrams don't show their relationship, I expect the hose should exit to the passenger side of the cat...

LukeaTron

^ That is correct. If it ever gets plugged you'll end up with about 2 gallons of stinky water hanging out in the bottom of your HVAC plenums. Guess how I know.