EGR delete is an option and probably much cheaper, looking at less than £100 for this at darkside but they do replacements as well for around £150 i think but depends on engine
Hi Its a bit of a trail for you but Darkside are in Grimesthorpe near Barnsley with an excellent garage almost next door, Porsche and Euro Cars. It would cost you much less than £600 to get it done there, plus you get to sample the delights of South Yorkshire