307 HDi SXi - peugeot problems - Hugo CJ

Dear All

Currently have a Pug 307 with Anti Pollution Fault - no deterioration in performance.

Reading is

Flow sensor signal. Open or short circuit to earth . Permanent (001) Is there anything I can do myself with this or is it a dealer fix? If so what could be the problem and any idea on cost? Am looking to sell so don't want tos pend too much if poss. Chris

Differential exhaust pressure signal. Open circuit or short circuit to earth. Permanent (002)