Having tried but failed to carry out a regen, it won't now let me perform another until it has clocked up another 31 miles apparently!

I have since confirmed that it was fitted with a none genuine DPF which is a little worrying but I still don't know how it calculates the DPF percentage when there is no back pressure to speak of. I have been monitoring exhaust gas temperatures and have noted that there is a difference between sensor 1 and 2 of around 30 degrees, sensor 1 being the highest, but I have no live data to compare these readings.