Here is a small guide to help you disassemble the air filter of your piaggio porter Np6
Where is the Piaggio Porter Np6 air filter located?
The Piaggio Porter Np6 air filter is located under the right seat (passenger side)
just lift the seat cushion to access the box that contains it
Disassembly Guide - Piaggio Porter Np6 Air Filter
1 - Loosen the screw of the retaining clamp of the sleeve entering the throttle body
2 - Disconnect the inlet hose to the throttle body
3 - Undo the fixing screws of the air filter cover.
4 - Remove the air filter cover
5 - Remove the air filter element