Hey Everyone, Here is a list of inexpensive tools and common Subaru connectors that you might find useful when converting (or building from scratch!) your own harness. Have fun!

Oh, and also, most all the Subaru stuff is from Corsa-Technic (I like their layout and ease of navigation), but Eastern Beaver, Ballenger Motorsport, Mouser, Digikey, etc also offer a lot. I'll be adding to the list as I get time, unfortunately I haven't found a very automated way of doing this!

TOOLS:

P-707 Hozan P707 Crimper You can get this crimper from many different outfitters (eBay, Amazon, direct). It'll crimp most connectors you find below.
Grote ratcheting crimper This is my go-to crimper for non-insulated/non-sealed connectors.
 Non-Insulated Butt Connector 26-24 Gauge Seamless - 100 Pack Sherco Butt Splices 26 to 10 AWG, an assortment is nice to have
Raychem DR-25 Heatshrink - Yellow Print

All Purpose Heat Shrink

Raychem

Adhesive heat shrink is a must-have. 2:1 double wall for splices, 4:1 for harness covering. Raychem is the best, but pricey.
KAPTON-TAPE20MM

Kapton Tape

Polyimide "Kapton" tape is used for high-temp areas that you want to protect further.
tesa PET Fleece Wire Harness Tape (51618): 5/8 in. x 82 ft. (Black)

Fleece Tape

PET Fleece Tape is great for keeping things organized in the interior. Tesa makes good fleece tape.
  Split Loom Braided split loom is nice looking and super flexible. It doesn't look stock, so if you're going for that OG vibe, use a standard plastic split loom like Subaru uses. Monkey Fab has all kinds of great gear for the DIYer including a split loom kit with lots of sizes - highly recommend.

Early EJ:

SUMI.A-SKT Heavily used in early EJ's (tin and gold)
  HM-16S Engine
  HM-12S  Engine
   MLC.HYB-26S ECM
   MLC.HYB-16S ECM
   MLC.HYB-12S-1 ECM
   MLC.HYB-22S ECM
   MLC040HL-SKT ECM pin Small (tin and gold)
   MLC070-SKT ECM pin Large (tin and gold)
   250.TL-SKT Main/Fuel Pump relay socket
HM-4P Oxygen Sensor
MT-1S Knock Sensor
HM-3S Camshaft Position Sensor
PL250-1S Starter Solenoid
250.AVR-4S-2 Alternator
 3 Pin SWP 070 Sealed Connector 3 Pin Yazaki SWP 070

Crankshaft Position Sensor

 

DBW 2005+

  MLC025/040III-31S ECM
  MLC025/040III-31S ECM
  MLC025/040III-35S-A ECM
  MLC025/040III-35S-B ECM
  090II-5S-1 MAF
  090II-6S-1 Pedal
  TS025-6S-2 Pedal, get some gold pins too
TS025-5S MAF, get some gold pins too
  RK/090II-54S  2005+ Engine
DL090-16S 2005 Engine
SUMI.B-SKT 16 Pin engine connector socket
  090II-SKT 090ll Large terminals
  RK.MS-SKT 090ll Small terminals
250.HL-PIN Main relay pins
PL250-1S Starter
HX090-3S-5 Alternator