First its best to follow along with whatever instructions that your gauge comes with. I opted to go with how Subaru would install the gauge.
Things you will need..
12mm socket and wrench
10mm socket or wrench
Flat head screw driver
Phillips screw driver
Drill with bits
Seran wrap or shop towels
coat hanger or like product
Knife or box cutter
To start remove your negative battery cable. This is one 10mm bolt.
Next taking off your intercooler. This is an easy 5 bolt removal. 2 on the turbo side and 3 on the bypass valve side all 12mm. You will also be removing the tube and vacuum line that is attached to the bypass valve. Dont forget to remove the intake tube from intercooler to motor. This is a flat head hose clamp.
It will take some working back and forth work the hoses off but be patient and be very careful to watch for those fins. Last thing you want is to run your thumb over them trying to remove the intercooler and bend 8-12 of em.
I chose to wrap all ports fromt he intercooler, and intake from turbo and to motor with seran wrap. This will help to keep debris and dust out. A shop towel will work in this case also. It is an optional step but my suggestion to you is take the extra effort.
With the intercooler removed we can now easily access the grommet on the back side of the firewall. This will be where we will run the vacuum line to the gauge. Go ahead remove that grommet. A flat head screw drive will come in handy here.
Now cut the vacuum line that ran to the by pass valve about 2 inches down. Place in the "T". You will now have to cut away some insulation that was behind the grommet we took off earlier. A pocket knife works for this. Use a coat hanger or like product to help fish your vacuum line through the hole. You will want to come from the passenger side to the drivers side. There is a metal piece of bulk head right behind that hole and will make life hard to run that vacuum line. The line will come out near your gas pedal.
Place the new grommet on your vacuum line and attach the line to the newley placed "T" section.
At this point you can go ahead and put back on your inter cooler and reattach all lines. Some zip ties are helpful to hold the vacuum line where you want it. I also lock tight my bolts to the intercooler.
Dash removal. The dash is like some legos. Every piece has an order in which it was installed. Find that reverse order and you will be fine.
Popping off your dash hood is a tough dude. You have to give it a good tug. Mine was in there pretty tight. But once you have one part started the rest will come loose easily. The hood pulls strait back. Place your steerign wheel at its lowest point to help make room for you.
Next remove the gauge cluster. Two screws on the top.
You will also be removing the dash trim around the radio... It pulls right off and is help on with clips. The radio needs to come out, its held in place with 4 phillips head. You can access the clock for the wiring this way, the clock comes loose by pushing two tabs on either side of the clock out and pushing the clock towards the motor (a second set of hands really helps with this). The side panel on the drivers side door will give you access to the dimmer wiring. these all pop right off with a little tug.
Use some tape to help hold on your template to drill. Drill out your holes and you you can then mount your gauge pod base. I used lock tight on the screws and bolts that hold the gauge pod in place.
Now you need to run your wiring. The harness that came with your kit will have 3 major ends. One connects inline to the dimmer which is accessed via the side panel. Another is inline for the clock, this is accessed via removing the radio. Run the line up through the dash in order to reach your pod in the way you see a best fit. Following the route of all the other wiring you see will be easiest. There is plenty of room for the wires.
You can see I ran the vacuum line and wiring through the hole that the dash wiring comes through.
Now is a good time to test the gauge and make sure it works.
If all is good finish running your wiring through the dash hood near your pod base. Attach the vacuum using a 90 degree elbow, attach wiring to your gauge. Snap all dash pieces back into place. With all pieces in place you can adjust the angle of the gauge to your liking.
Check and listen for leaks. If you follow your standard instructions and use this guide you should be fine.
Please follow this adobe file along with this guide. The adobe file is the original directions for the SPT gauge. Using both guides can help you a great deal. http://techinfo.subaru.com/html/down...?doc_id=270503