Q: How to remove and replace fuel injectors and Fuel Rail on a Nissan Altima?
A: Remove the engine cover, if equipped. Relieve the fuel system pressure. On 2011 and later four-cylinder models, remove the air duct. 2011 and later V6 models should remove the wiper arms and cowl cover. Remove the strut tower bar. Remove the Throttle Body. On four-cylinder engines, remove the intake manifold. On V6 engines, remove the intake manifold collector (upper intake manifold). Disconnect the fuel supply line from the fuel rail. Disconnect the electrical connector from each fuel injector. Remove the fuel rail mounting bolts. Carefully lift the fuel rail from the engine with the injectors attached. Remove the injectors from the fuel rail, then remove and discard the O-rings. Replace both O-rings of each fuel injector and lubricate them with clean engine oil prior to installation. Install the injector retaining clips and insert each injector into its bore in the fuel rail until the retaining clip snaps into place. Always use new injector retaining clips on 2011 and later models. The remainder of installation is the reverse of removal. Reconnect the battery and perform the necessary re-learn procedures.