Nice to hear you got it sorted. However did we get by with EFI before updates - can't understand how it suddenly became neccessary to update an ECU, surely if it was made properly and coded correctly at R&D stage it would just function correctly until the car fell apart around it (like they used to) with the obvious exception of ECU failure.
Any idea why your car had this fault develop - I mean what changed within the ECU/car to make this an issue?
That's the million dollar question isn't it? Not sure, the egr was very clogged up, don't really see why this would change the settings? Perhaps as everything gets worn the tolerence isn't great enough, I think that's basically what the update does, just widens the acceptable tolerence before logging a fault code. All good to date anyway.