gents, I think I know the answer to this but would like some confirmation, 6 months ago I had the head gasket replaced due to overheating issues, this sorted the overheating but the disco was never quite the same, a bit lethargic and lazy. Recently it has been running very lumpy so I plugged in the Nanocom to see what was going on, nothing jumped out and I suspected a dodgy injector, as a precaution I changed the injector harness, it was them that I noticed the injector order in the head was the reverse or the Nanocom data, I assume the Nanocom uses cylinder 1 as the timing chain end of the head, it this correct?

If you mean the order of how the codes are stored then yes, you must store the codes starting from the front of the engine one after another

Okay thanks for that, as the injectors have been replaced in reverse order that would explain the lazy running.