The component with the lowest price in the EXHAUST 1 schematic is the Clamp (6e5).
On this parts fiche the Bolt (663) is the most specified component.
A sample from the products for the Exhaust 1 include: Bolt Washer Based Head (6m6), Gasket, Exhaust Pipe (nas), Clamp, Hose(6r7), Washer, Plain (646).