Espace Mk1V 3.0 dci 181hp

Hi, I have a strange issue with my espace, when engine is put under load it hesitates quite a bit between 2/3 thousand rpm, if I ease off a little I can drive through it but it still happens under any acceleration. I've put a new air flow meter on it, egr valve was clean but I've blanked it off anyway, there are no vacuum leaks and no leaks anywhere on inter cooler or pipes, no faults showing anywhere under diagnostics either.
I'm now completely stumped as to what's causing this.
Has anyone got any ideas I might have missed ?

Espace Mk1V 3.0 dci 181hp