Are you talking about the smooth thin "s" pipe?
Edit:
If yes, it's a coolant hose
I'd recommend having a water bottle nearby to catch dribbles
Edit2:
After doing a little more research; It is more specifically your water bypass hose.
Part no. Genuine Honda (19509RNAA01)
Edit:
If yes, it's a coolant hose
I'd recommend having a water bottle nearby to catch dribbles
Edit2:
After doing a little more research; It is more specifically your water bypass hose.
Part no. Genuine Honda (19509RNAA01)