Matty audi man

Hi all. Just registered today and have a question please. Just brought a a4 2 litre petrol fsi engine estate 2003. It's done 112k miles but the epc electronic power control?? Comes on the dash and makes the car only rev to 1k... The garage have changed the air flow sensor with a genuine sensor and it looks like the cam shaft sensor is new too... (Could be a copy.. Cheap type??) Has anyone else had issues like this? Thanks. Matty