The component with the lowest price in the WATER PUMP-SENSOR schematic is the Nut,flange,8mm.
Some items from this specific schematic: Passage Comp.,wat, Sensor Assy,tw, Pkg, Egr Vlv (nas), O-ring 3.1x20.5.
The twenty-five Pilot 2004 (4) 5dr Lx (kl,ka) Water Pump-sensor component parts are all listed in this schematic.