Pug 206 cutting out

[arcon]

Hopefully somebody will have experienced this:

206 2003 1.1L engine
Randomly cuts out - sometimes when i blip the throttle and it drops; or slowing down; but can also do it at other times
Random misfire and irratic revving at times
Error codes: cylinder 4 injector circuit; fuel pump relay circuit

So i've been ruling things out, testing components and swapping with another 206 here:
swapped injector 4 with 1 and no change of cyl 4 to 1 in error code
resistance test on injectors, consistent across the board
replaced wiring loom for injectors
replaced the relay pack that's in the engine bay
checked live data for any irratic MAP data, air temp sensor, injection pulse
can't see any damage to any wiring looms, but will further investigate this
repalced whole throttle body including idle control valve


Not sure where to go from here..