96 legacy L fuel question

[Skippy213]

Any one know under the back of the car the fuel lines run from pump to tank and some plastic looks like for air vent thingy(part in question)

I recently had a hose rupture and I simply swapped old with new one by one and now I have a high pressure leak. I am not able to get the clamps tight enough. I finally got new ones and now it is leaking further up.

I am lost as to what happened all i did was change hose for hose, could it be the plastic unknown part that is causing this issue and does any one know what that part is?

 it is an ej22 2.2 motor 

also incase the question arrives, the car does run just leaks like crazy.