To change an XR2i/XR3i/OFAC loom to OFAB:

you need to move firstly Pin 27 to Pin 8 (CO Pot)
Then move Pin 45 to Pin 27 (MAP Sensor)
You will also need to change the MAP Sensor plug. And it is advised to wire in the condensor in with the MAP Sensor Signal wire.

When changing an XR2i/XR3i loom to either OFAB or OFAC you need to cut the Blue/Yellow wire from Pin 2 of the EDIS4 (runs to Pin 28 on ECU)