A few tips:
- When replacing the rear plugs, getting the coils out of the way may seem impossible, unless you unplug it from the wire harness and turn it upside down 180deg then try removing it.
- When removing the nut on the passenger-side rear coil, you have to use an offset wrench, low-profile ratchet/socket or 12mm univ-socket. The space is tight back there.
- When unscrewing the plugs, some may take much more effort than you think is needed. When I did mine, 3 of them I could finish unscrewing with my hands but 1 was tight until the last thread that I thought it was cross-threaded, but it does not look like it is. I was able to screw it back in with no problem but still took way more effort, more than the 15ftlbs of torque, than I felt comfortable. Since my dealer was the only one that touched the plugs before I started doing my own. I took to them and they stated that sometimes the plug threads may be dirty and therefore screwing them in may take some effort. I tried to again to make sure and it screws in and out but still with a lot of effort.
- After screwing in the plugs and when putting the coils back on, make sure that the coils are flush against the head. If there is any in/out play or spring-action from pressing on the coils, then plugs are not all the way in. Again I learned this the hard way, when I stopped screwing in my final plug too early since it was taking a lot of effort.
- You do not have to use anti-sieze. The Subaru vacation pix only suggest using motor oil on the threads and in doing so make sure to only apply 1/3 of the specified torque when screwing them in.
- When removing the intake, it is gonna make it easier if you remove the flexible intake connector first.
For me, the minimum required tools were:
- Extendable magnetic wand and tray (Life savers)
- 10mm 3/8 drive with at least a 10inch extension for the intake
- 10mm wrench for the bolt holding the intake
- 12mm 1/4 drive and 12mm offset wrench for the coils
- spark plug socket + univ joint + >=4 inch extension 3/8 drive to unscrew plugs
- Pliers to pull spark plug socket off plug after screwing back in