Ralph, Whilst you say there are no EML warnings - have you obtained any professional Diagnostic Codes (DIC) ?
What made you consider the EGR required cleaning? What service history? Is DPF burning clean?
Forum system is identifying you from UK ?

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No DTCs. EGR was suggested as a possible cause by MOT garage. FSH. O&F changed every 6 months / 5k miles. Full service every 2 years / 20k miles with all filters. DPF regens every 3-4 months with no known issues. Yes, in the UK. Trouble is vehicle value only around £1500 hence the post

 

Looks as if you've done your best in looking after your vehicle. Maybe other members can suggest a possible cause(s).