How to Change an A6 Injector

1. Turn off the ignition. Remove the fuse for the fuel pump, using the list on the fuse box as a guide. Start the engine and allow it to idle until it stalls. Turn the ignition off and disconnect the negative battery cable with a socket wrench. Replace the fuel pump fuse.
2. Wrap a clean shop rag around one of the fuel-line connections to the fuel rail. Loosen the retaining nuts for the fuel line with a socket wrench to relieve the pressure in the fuel tank. Properly dispose of the rag.
3. Remove the retaining nuts for the fuel lines, and detach the fuel lines from the fuel rail. Disconnect the mounting bolts for the fuel rail with a socket wrench, and remove the fuel rail from the intake manifold with the injectors still attached. Turn the fuel injectors counterclockwise to remove them from the fuel rail.
4. Mount a new lower gasket to the nozzle end of the fuel injectors. Clean the threads of the fuel injectors with a clean shop rag, and apply a thin layer of thread-lock compound to the threads. Screw the fuel injectors clockwise with a socket wrench to install them into the fuel rail, and mount a new upper gasket to the open end of the fuel injectors.
5. Mount the fuel rail to the intake manifold, and fasten the mounting bolts with a socket wrench. Connect the fuel lines to the fuel rail, and fasten the retaining nuts for the fuel lines. Reattach the cable for the negative battery terminal.