I have done all sorts of fords but not the i4. Weight and the costly camchain meant I went the Zetec path.
one I did earlier
https://passionford.com/forum/restor...n-frs-ecu.html
have you got the Rs 2000 ecu and loom ? If not it’s a non starter as there won’t be enough pins in the Sierra ecu to modify.
If you have, look at the pcm / ecu plug it is numbered 1 to 60. If you list 1 to 60 with the colour of the wire next to it I will look up what wire does what on a program I have. I need the colours as the program will list multi options depending on Pats or non pats and other things.
for example
pin 1) orange / yellow trace is kam ( keep alive memory ) permanent 12
pin 2) no wire.
pin 3) white / violet trace is the speed sensor in the gear box.
pin 4) no wire
pin 5 depends on pats and so on.