I recall that there are a few threads on this about a rubber seal or gasket that can be replaced at the Electro-Hydraulic-Actuator (EHA).
This box is doing the adjustment of what the O2sensor wants to be done, i.e increases and decreases the fuel pressure.
That probably is your problem.

At the pumps, depending where it leaks, sometime tightening or new copper washers can be enough.

Good luck

Reinhard