Q: How to remove and install the secondary air injection system and Air Injection Pump on a Ford Fusion?
A: The secondary air injection system is only on 2.3L four-cylinder models. Disconnect the negative battery cable. The pump is at the engine compartment's lower front. Raise the vehicle and place on jackstands. Remove the underbody cover and disconnect the pump's electrical connector. Disengage the wire harness clips from the pump air hoses. Disconnect the inlet air hose from the air intake duct and the air hose from the diverter valve. Remove the pump mounting bolts and remove the pump and hoses. Use the same hose clamps to secure the hoses to the pump before installation. The secondary air valve is behind the left rear corner of the valve cover. Disconnect the vacuum hose and the outlet and inlet hoses from the air valve. Remove the air valve mounting bolts and the air valve. Reverse these steps for installation.