EGR issues need you help

[audi-a3-koe]

I have been having EGR problems and need to replace it but been researching and getting a bit confused. Firstly can you tell me plz where the EGR is placed? Also where can I get a cheap decent EGR valve?

My car is a Audi A3 2.0 Fsi sports 2004 make (53 Plate)

Need your help plz