Barcelona, not UK. Part is coming from UK Should be the same ECU? Mapping might be different due to emission regulations, etc (I know on bikes this happens).

It cranks. Fuel pump appears to be ok, but no spark. All fuses ok.

Will try disconnecting battery next time if happens (if it does before part arrives).

Any damage that can happen because of driving for a week with a problematic oxygen sensor? Will it ruin my cat?