I have a engine problem with my citroen saxo fault code 292 and 295 ?

citroen saxo 1.4 T reg. when I accelerate the engine power drops off and the fault light comes on, if you eas off the accelerator the engine picks back up and the fault light goes out. the fault codes are 292 -fuel adoption fault and 295 - fuel trim error. I have renewed the fuel filter, throtle potenciometer,idle control motor, and oxeygen sensor. none of these have made any difference. Any ideas