have they checked the fuse for the o2 sensors not the 1 in the fuse box
the 1 for the o2 heaters it behind the fuse box
and a pcm recal for o2 sensors
and cheap cats find it hard to pass they mot and go nowhere near fords shit limits
p.s. i work for shit ford aswell
420 must be the fitted price they are only 310 to buy