Many thanks for the quick reply.
My car is a late 2004 car, registered in September. The back exhaust is damaged at the moment so I cannot get a sound file for you at present as it's too loud, but this should be fixed on Monday when the parts arrive.
The power and hesitation is esp at low speed, at the top of the rev range it seems ok but noisy. Offset cambelt??? That may be something I need to look into, would the ECU not pickup on the cambelt issue or is a visual check required?
regards,
MrB