Install the heater housings on the lower intake followed by the upper intake, using the supplied gaskets. Again, pay close attention to the order of the fasteners and their washers. They're designed to withstand the vibrations of the engine without loosening. The grounding straps for the heating elements (A) must be carefully bent over the intake once it's in place. On California models equipped with an EGR valve, install the metal gasket in the upper intake (B).