2007 Legacy2L GT(BP) Link installation

Hi, we have come across an issue during the reflash tune process of a 07 BP Legacy. We are unable to recover the ECU or find a suitable used unit.

We want to install a Link G4+ now. I've heard that people have done this in the past with one of the WRX Plug in Links. If anyone has experience with a similar conversion could you please point us in the right direction. What wires have to be re-pinned? What version WRX Link did you use? How did you make the CAN Bus side of things work?

Any pointers would be greatly appreciated.