2006 Eng Fault Light

[godoyi1452]

My 2006 S40 has been displaying an orange eng light for a while and a visit to a diagnostic centre indicated a Cam angle sensor, which was changed but resulted in the light reappearing 200m down the road. Apart from rough, high speed idle on cold start and an apparent lack of power on hills, the car runs "normally". I also feel the consumption may be a bit high.
I am loth to throw money at apparent solutions and would like some suggestions as to a positive course of action.