renault espace 2003 2.0 turbo auto

[stinkything]

Hi all , i'm thinking of up dating my 1998 espace for a 2003 petrol turbo auto . the car starts and drives but if you drive her hard there seems to be lack of power (as if the turbo isn't working ) this point was pointed out to me by the owner hense its cheap . Could it be anything apart from the turbo ? Many thanks Leigh.