Before I start ripping bits off the engine though, I want to take a closer look at the complex wiring and see exactly what we are dealing with here. Like most modern cars, Subaru have also inconsiderately covered everything up very nicely with lots of plastics and dash panels. Hanging from the Ignition key is also an indication that we will have some serious security issues to overcome in the form of a high end alarm and immobilizer.
WARNING Before you attack any modern car, just have a quick look about and determine what it has in the way of Supplementary Restraint Systems (S.R.S.). Look for Airbags especially. Steering wheel centre and passenger dash board ones are usually obvious, but also look for seat bolsters and side curtains on the A-Post and B-Posts. Anything fitted will always have an AIRBAG symbol as a warning, and seats will have a badge sewn on to the sides. Look carefully at seat belt mechanisms, as they can often have explosive charges fitted to pull the belts tight in the event of a crash - they look like thin cylinders running down the sides of the chairs. They usually catch people out, and can take your fingers off if you are a bit rough in removing the seats. Next time you open the door of your daily driver, have a quick nose about and see how many you can spot. Always disconnect the battery before messing with Airbags and always have a cuppa before you disconnect anything, as it allows the system to fully discharge (20 mins) once the battery has been disconnected.
A quick look around tells me that this particular vehicle has an airbag in the middle of the steering wheel and one on the top of the passenger side dash. The seats are clear of anything, but there are explosive charges wrapped around the front seat belt mechanisms located within the B-post. Although I cannot see it yet, I expect there will be an Airbag Control Module somewhere near the tunnel and some impact crash sensors located somewhere behind the front bumper or corners of the wings.
Obviously I am not going to be hanging upside down in the foot wells here, so I have disconnected the battery, had a cuppa, and then set about removing the seats and dashboard so that I can locate this troublesome ECU and all of its wiring. A top tip here is to plug everything back in afterwards to check that it all still works, and then you can set about removing one circuit at a time. With so much being controlled by the ECU, you really do not want to start cutting wires just yet.

Lets get the dangerous bit out of the way and deal with these airbags then. This is the bit that scares many people, but as long as you follow some simple rules, and treat them with respect, you needn`t worry. First some do`s and don`ts. Airbag wiring in cars is very easily identified as it will always have a yellow sleeve and yellow connectors on anything dangerous. Look at the picture above and you will see the yellow wires from the passenger airbag all the way down to the control module with a big yellow sticker on top of the tunnel - right where I suspected it would be.
NEVER unplug any wiring with the battery connected, and
NEVER go near the wiring with a multimeter. So, disconnect battery and sit back for 20 minutes whilst waiting for the system to discharge itself. Once that has been done, simply unplug the airbags, sensors and remove the control module. These are all worth good money too, so remove them and put to one side. On that note, you
MUST store these items with the bag side facing upwards, so if they do go off, it will just deploy as normal with a loud bang. If they are stored bag side down, they will literally take off like a rocket and will cause serious damage and injury. You can now trace and remove all yellow wiring, its not needed.
I can hear you all screaming "Holy F . . . " at this point along with the thud of your jaws hitting the floor, but to be honest, I`m in my element here as this bit really doesn`t phase me at all. The next step is to make it all look really scary by removing all the insulation tape holing the wiring loom together so that we can separate out the wires and start working out what we need and what we can simplify.

I have now reconnected the battery so that I can start the engine and hope that everything still works, which it does. With the safety systems now dealt with, its now time to focus on the security systems and make life a lot easier by removing them also.
All cars produced after 1996 must have an immobiliser fitted. Usually this is down to a small chip built into the key, and we shall deal with that one later, but for now, I am ripping out the Subaru Thatcham Category 1 Alarm and extra immobiliser system that was also fitted as an upgrade. I don`t want to go into too much detail of how to remove it on a public forum, but to give you a heads up, its a Sigma M30, a brilliant system in its day and the wiring is fairly easy to trace if you have got to this stage. If you do encounter problems though, please let me know as I was actually trained by Sigma and have the full schematics for this system. What I would suggest though is to have a large bucket of water handy. The siren has a back up battery inside it, and if the alarm wiring is tampered with or wires cut in the wrong sequence, it will cause the siren to go off, and when it does, there is nothing to stop it. So, remove the bolts holding it in place, unplug the wiring quickly and throw it in the bucket of water where it will silently burble away to itself for the next few days.
The main ECU that we are looking for is pretty well hidden, and its not until you remove the foot plate on the passenger side that its location is finally revealed.

Now that everything is visible, we can start to mess about in removing unwanted items and circuits. Things like windscreen wiper motors and washer bottles are not connected to the ECU, along with the stereo and fog lights. These parts can be removed and sold, and the fewer wires we are left with, the easier it is to work out what we are doing.