Changing the fuel filter is a regular maintenance item that should be performed on a regular basis. I would say that changing it out every 30K-50K miles should be good to maintain as new performance for your engine, or at least maintain the fuel system in good working order.
To change out the fuel filter on a 2006 Audi A4 you will need to jack up the passenger rear of the vehicle, since the fuel filter is located underneath the vehicle just before the rear wheel.
I used the mount point for the rear lower control arm as my jack point and with my hydraulic jack, rose up the vehicle.
I also used the bracket that the lower control arm was attached to for a jack stand; remember you need to always think of safety! You don’t want to get crushed changing out a stupid fuel filter!
There is a plastic piece that is covering the fuel filter location and keeping it safe from debris. You will need to remove the two plastic bolts to take this plastic piece out. I believe that the plastic bolts can be removed with an 8mm socket, but it’s possibly a 6mm or a 10mm. I just loosened them and took them out by hand as to not damage them.
You will also need to remove the two torx screws that are mounting the plastic to the actual car.
Once the two torx screws and plastic bolts have been removed, you will be able to slide the plastic piece out and remove it from the vehicle. This will expose the fuel filter.
There are 3 lines that are connected to the Fuel Filter, a Fuel In line, a fuel Out line, and the fuel vent return line that goes back to the gas tank. Make a note of their locations and remove.
The way to remove those clips is to press on the white/blue clip,
which will release the clamp on the filter, and slide the hose in, a little
bit, then pull it off. You probably don’t
need to slide the hose in, but I found it came off easier that way. They are a little difficult to get the clips
to release properly, but you do not want to break them, so take your time and
You will also want to be prepared for some fuel to be
spilled since these are live fuel lines with fuel in them, it’s not much but it
will be spilled.
When all the lines are disconnected, you will want to loosen the torx screw that is holding the fuel filter in place. Don’t remove it; just loosen it so the fuel filter can slide out.
Slide the fuel filter out of the bracket; you will slide it forward, towards the front of the vehicle. Once it is removed, you will want to dump the excess fuel into a catch can, or back into your gas tank.
Put the new fuel filter in place. Connect all the lines and tighten the bracket bolt so that it is secure.
Re-attach the plastic cover for protection and you are done!