Ok just to add to that, ive just whipped out my OFAB loom as its in the room, and my CO Pot signal wire is on Pin 8.

Ive just been re-reading that Fiesta Turbo guide.....its actually really pants, if you read the first one (XR2i - OFAB), it states the pin changes, then the next one (XR2i - OFAC), your doing in reverse all the changes needed for OFAB (returning it to how it was, an XR2i loom). So, cut a long story short, the XR2i loom in the first conversion is wired different to the one in the second conversion Uhhhhhhhh..........NO!

SO anyway, i believe your CO Pot wire should be on pin 27.

Let me know how u get on because theres also a variation on the MAP sensor wire concerning Pin 27 aswell, that Fiesta Turbo guide is well confusing, we'll sort this one out