On the thermostat housing there is a pipe that is about 6inches long and its in the shape of a cresent moon vertically up and down on the back of the motor to the housing.. what is it called so I can swing by and pick one up? this is a d15 btw.

 

think its a bypass hose but not sure. go to honda and have them show you on the computer to know for sure

 

here is a honda part number if you are still in need
Honda part # 19508-P08-000

 

nailed it..bypass hose it was. 7.86 Thanks.