Last Updated
06 December, 2004


APEXi Power Intake Installation

 The APEXi Power Intake is one of the more highly rated aftermarket air filter units for the MR2 Turbo. It offers high flow plus excellent filtration. That last item is sometimes missing in competitors' products.

Installation requires removal of the stock air filter and airbox, and is reasonably straightforward. The only problems center around the APEXi-supplied instructions. First, they are in Japanese. Second, they include some incorrect diagrams. Hopefully the photos I included here will clarify some of the assembly. All of the photos can be clicked on for a larger image view.

Finally, remember that this is only a guide -- not gospel. What you do to YOUR vehicle is YOUR responsibility. I do not endorse, approve, authorize, or otherwise encourage you to make alterations to your vehicle. Be careful, and recognize the dangers associated with modifications to your vehicle's critical systems, like electrical, engine, brakes, etc.

Please contact me if you have comments or suggestions about the article or the project, or if you find errors on these pages.

Tools Needed

  • Flat-blade and Phillips screwdrivers

  • Pliers

  • 10mm, 12mm and 13mm sockets and wrenches

  • Socket extensions in a variety of lengths

Doing It

Open your engine lid and remove the left side trim panel. Look down at the Air-Fuel Meter (AFM) assembly, and locate the electrical connector, shown inside the red circle below:
Apexi-001.JPG (130931 bytes)
If you haven't been warned before, heed this warning now:


To remove the connector, slip a small flat-bladed screwdriver under the ends of the spring clip that encircles the plastic connector. It's only necessary to lift it out of the side grooves a bit, then the connector easily slips off:
Apexi-002.JPG (102695 bytes)
Move the connector out of harm's way for now.

Loosen the two hose clamps shown inside the red circle below: 
Apexi-003.JPG (124209 bytes)
Unsnap the four clips on the air filter box. There are two on the left end:
Apexi-004.JPG (93295 bytes)
One on the right-rear corner:
Apexi-005.JPG (80248 bytes)
And finally one on the right-forward corner:
Apexi-006.JPG (95593 bytes)
With these unsnapped, you can lift the top of the air filter housing out, twisting it to clear the body and easing the hoses off at the same time.
Here's the entire assembly out of the car:
Apexi-007.JPG (78876 bytes)
Next, remove the air filter element:
Apexi-008.JPG (98531 bytes)
Remove the three 12mm mounting bolts that secure the lower half of the air filter box:
Apexi-009.JPG (92236 bytes)
Once these have been removed, you can pull the housing out of the car, with a little twisting to separate it from the airbox assembly (plenum) that has not yet been removed.
There are two 10mm bolts and one 10mm nut holding the airbox in place. The bolts are captured to the airbox, so you don't need to worry about dropping them once they have been unthreaded.

One bolt is located just inside the left hand air scoop.
Apexi-012.JPG (60411 bytes)

I found I could reach it with a long 1/4" drive socket extension:
Apexi-015.JPG (93049 bytes)
Another 10mm bolt is located directly under the airbox:
Apexi-014.JPG (76078 bytes)
Finally, remove the 10mm nut above the top of the airbox:
Apexi-013.JPG (111679 bytes)
You can now remove the airbox from the car. 
There's lots of room now, a precious commodity in the MR2's engine bay:
Apexi-017.JPG (109055 bytes)
Back to the workbench, you'll need to remove the top half of the air filter housing from the AFM assembly. There are four 10mm nuts and one 10mm bolt to be removed.

Remove the bolt from the flange near the intake hose:
Apexi-018.JPG (81681 bytes)
Next, remove the nut inside the housing near the AFM opening. You'll need to bend the metal flange out of the way to reach it:
Apexi-019.JPG (94835 bytes)
Next, remove the three nuts on the outside of the housing:
Apexi-020.JPG (111233 bytes)
The housing can now be pulled free from the AFM assembly, although the plastic flange (where the 10mm bolt was fastened) needs to be separated a bit to free everything completely.
Apexi-021.JPG (86988 bytes)
Don't lose the rubber gasket, as you'll need to reuse it with the APEXi unit.
You can remove the two Phillips screws attaching the metal bracket that will no longer be used:
Apexi-023.JPG (99393 bytes)
Now, mount the APEXi mounting adapter to the studs on the AFM assembly. Note that the APEXi logo faces up:
Apexi-022.JPG (128314 bytes)
For the next assembly, you need about four hands. It can be done with two, but there are many parts to keep in alignment as you attach the bolts. Because of this, I could not take photos as I progressed, so I'll show you the finished assembly and describe the process:
Apexi-026.JPG (116028 bytes)
Set the air filter element on the work surface with the threaded inserts facing up. 

Place the gasket on the filter element, and align the holes.

Set the entire AFM assembly on the gasket, making sure to align the holes.

Try to get the back-side bolt (the one that's hidden from view in the photo) in place, as it doesn't need to secure anything but the adapter to the filter element.

Place the hood in place, and try to get one of the bolts aligned and installed. I recommend the one on the left in the photo above, since you don't need to wrestle with the mounting arms.

Once you have two bolts threaded, the remaining two should be a breeze. The mounting arms are shown in their approximate position for installation. You can loosen them a bit during mounting, but the other bolts should be tightened securely at this stage.

NOTE: The APEXi drawings, at least the ones included with my unit, are misleading at this point. It's best to ignore them and follow the photo when installing the mounting brackets.
Take the entire assembly and place it in the engine bay. You'll have a tight fit as you try to fit the intake hose back over the plastic elbow. It WILL fit eventually.

Install the APEXi-supplied bolt (13mm) into the lower mounting plate as shown below. Leave it a little loose at this stage.
Apexi-028.JPG (108464 bytes)

Remove the 10mm bolt that secures the support for the coolant filler neck, and re-attach it through the other mounting arm:
Apexi-024.JPG (118650 bytes)
Once everything is connected, go back and tighten the mounting bolts. Re-connect any hoses and tighten the clamps. Re-connect the AFM electrical connector, and make sure the retaining spring is secure.

Here's a view of the finished unit in place:
Apexi-031.JPG (111674 bytes)
There's extra room left over!