A4 & S4
WARNING: This page is about a different car, the 2001 Audi S4 and 2001 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.
Loosen fuel filler cap to release pressure in fuel tank. Remove fuel pump relay. Fuel pump relay is located in position 4 of micro-electric center in driver's footwell. See Fig 1 . Start engine. Allow engine to run until it stalls. Turn ignition off. Disconnect negative battery cable. Slight pressure may remain in system. Before disconnecting any fuel system line, cover connector with a clean shop towel. Reinstall fuel pump relay.