The fuel filler pipe had been redesigned for the 2006 model year to eliminate the spring loaded steel "flapper."
The new design will be phased in when the existing stock is used up.

On the earlier design with a plastic filler pipe, the metal flapper was part of the ground path for electrostatic discharge when the fuel fill nozzle is inserted.

In the new design, a metal pipe with metal restrictor serves as a ground path without need for the flapper.

This is normal. Do not replace any parts for this condition. If the fuel filler neck with flapper door is replaced, the service part will be missing the flapper door.

Team ZR-1
True Custom Performance Tuning