You know that i had a problem with not having any warning lights well there was a good reason for it someone before i owned the car had cut through the circuit in the back of the instrument panel due to the airbag warning light being on.
Anyway the engine management light does not stay on but there is still the o2 sensor fault code showing up when the diagnostic machine is plug in.
So my fella (Tom by the way) at the garage believes exactly what you said Tom that the ecu is not responding to the ecu.
We are currently still awaiting a donor ecu with keys so that we can test the emissions on a different ecu.