OBD Reading

[Niall]

from 96 they had an obdII socket but the protocol used was still a funny manufacturer specific one in pugs untill 2001, the only exception is HDis. just because it has an obdII port doesn't mean it will connect. tried many 306s with an ebay scanner, will connect to all HDis but none of the others, not tried post 2001 306s though. the only non hdi that i have been able to pull codes off were ph1 petrols but those were flash codes so doesn't really count

Sorry but that's not true at all. As part of the protocol, if a manufacturer wanted to use the obd socket, the car had to be obd compliant.
I also know that Peugeot have used obd before 2001 on several models because I have tested some!