The original issue i believe is down to the cap sensor. This has caused all additive(or most of it) to be injected into your fuel tank, this has caused DPF to start blocking prematurely, the vehicle has been trying to regenerate but cant due to glowplug failure which compounds the blocking of the DPF. The original misfire/egr fault I suspect to be caused by excess soot from failed regeneration
All a bit longwinded but hope this helps
MARK