Hi mate,
It wont be your lambada, because the JTD doesn't have one. Also, it should only take a couple of drives for the ecu to sort itself out. EGR is a possibility.
Cheers,
Alan
I had the EGR valve cleaned a few months ago when I had a new MAF - could it have got clogged up again due to the overfuelling? I'll strip it tomorrow morning at work....