This is a very simple and easy procedure and can improve both interior smell and heater/air conditioner operation by improving air flow, and reduce any smell. This should be done annually or at 15K increments.

I am writing this as a general article as the procedure is pretty much the same throughout the FM line and I will add side notes in Italics for the M. These models differ slightly, the basic procedure is the same. You need to use some common sense when applying force to ANY interior panel, remember they are only plastic.

Skill Level 2 of 5

Time Required <30 minutes

Tools and Equipment Required;~#2 Phillips screwdriver~ Small pocket screwdriver, or suitable device~Mircofilter of your Choosing (see note below)

Procedure

1- It is always best to start trimming out any panels that may be damaged during this. So remove the sill plate, this is done by gently pulling at the front upper edge.(The area closest to the bottom of the glove box) Pulling towards you in one gentle motion to prevent damage or deformation. Remove and set aside.

2- Remove the lower right kick panel now. This is done by removing the black plastic nut, turning counter clockwise with your fingers should suffice. Removal of this trim panel is done by unlocking the pawls (3 locking tabs on the rear section of the lower right trim panel), I find that sticking my fingers in the small gap and gently pulling removes it with less chance of breakage. Be careful the edges can be sharp, I have cut myself several times doing this but I would rather injure myself than a trim panel.

06+ M owners may now want to remove the side cover, on the right most edge of the dash.

3- Now locate the two lower screws on either side of the glove box. Remove and set aside.

4- Open the glovebox door and remove the four screws. M owners will need to remove a cover over the latch.You will also want to separate the box door from lower locking tabs. Pulling up on the left side GENTLY first will unlock the tabs and not hyper extend the cord that is attached on the right side.Now you will need to unlock the tension cable, depending on the year you will either slide a locking tab or release a loop in the cording. Set the door aside. Now is a good time to remove the blower motor cover by pushing towards the floor and once the tabs are released pull towards yourself.

5- At this point the inner GB assembly is separated by gently pulling on the lower section there are 4-6 locking tabs (depending on the model). Once the tabs are released and the box is only being held in by the connecting wires, you will need to open the connector for the Valet switch by unlocking the connector (On the G the white connector is facing downward). On some models there will be a large yellow connector. This is the passenger air bag connector and special attention MUST be payed that the KEY IS OFF and out of the ignition before unlocking the triangular connectors sticking through the plastic piece of the GB. It's better to be safe than sorry.

6- Once you have removed the box components and set them in a safe place Note: they scratch easily on concrete and can also scratch other trim panels. So keep an eye out when setting everything aside. There is a white box almost in the center with a horizontal rectangular cover. Locate the tab on the right side and GENTLY pull towards you. Once this tab is released a very gentle up and down motion while pulling toward the right will release the two locking tabs on the left side of the box. (There are many sharp metal and plastic parts under there and blood is hard to get out of light color carpets.)

7- Once you remove the old air filter and without turning it upside down put it out of the car. You can spray a deodorizer or antifungal spray inside the heating and AC box. I like spray Frebreeze or something similar. Allow some time to dry and work before turning the blower on (~30 min if possible). Install the new filter, Note any direction indicated on the thick edges of the filters, many are directional.

Reassembly

Re assembly is pretty straight forward just a reverse of the above. I cannot stress this enough Take Your Time all of these panels are several hundred dollars a piece and damaging them might cause squeeks and rattles and poor trim lines. Taking a look at each piece as you put it back will show you where the locking tabs that need to be aligned before you push them into place, this will aide you next time you perform this simple maintenance item.

Note: Mircofilter Selection

Nowadays, there are many choices in Factory Replacement mircofilters. Although there are aftermarket alternatives if you do some hunting you can find a deal on a higher quality OE replacement. Infiniti offers three basic types of Mircofilters (at time of posting) The FX and G can use a coated paper filter stock, there is also an activated charcoal filter available that removes most odors from outside air. There is also now a Grapeseed Seed Propylene(click the link for a discussion about this) activated filter that the FX50S uses. Another member posted success with putting this in his G and the FX uses the same filter so it will fit all FXs. At the time of posting the M only has an optional charcoal filter, as it's filter is slightly larger.

Good Luck