Assembled and coding a canbus DCCD message emulator. It can send random or preset messages over canbus.   Working on the graphic interface for the receiver which just displays the current state.   once that works I’ll connect it to the car diagnostics port and live test it.

Yeah that stuff was via archive.org since it was no longer on the original sites.   Next note 2007-2014 GR GD have a wire to the TPMS lamp, not via canbus like the 2016+ cars. The TPMS can send canbus messages as it is in the unit that does keyless entry. It’s in the hatch area on left. Only one panel around the rear quarter window needs to come out to undo the one bolt holding it in. To interface with dash lamp any aftermart unit will need make use of the wire to dash cluster not canbus.   Seems DTC codes may be blinked out for all modules is via the dash. within 10 seconds  acc on Headlights on trip button 3 times headlights off trip button 3 times page 2796 service manual has table of what the results are.        

@THUNDA found ox336 Bosch one was 3 wire a few months ago. Maybe he can confirm.   https://www.aliexpress.com/item/1005007400474415.html has lots of images and explains the two different 3 wires versions.   Shipping is free over NZD$16 and that is $26.45 when logged in without the welcome deal price. Add gst and that’s still about $30.

I haven't considered it, no, but at the moment I am getting carried away restoring the car than driving it   A friend and I went to replace the o2 sensor, but it's well jammed in the header so we popped down to Pick-a-Part but all the 2L subaru's had the headers sworn in half, I guess to get the CAT out easier, FML.   In saying that - would anyone know the part number or what 3 wire o2 would fit an EJ204 ? The internet doesn't know about these motors until 2005+ ararrrgh

I had my last one done in south Auckland. Before that I used felt on dash and the A pillars.     But after watching how it was done, and realising the tool is around $25 next time I’ll give it a go myself.