Hi plz help I’ve got my first octavia vrs 1.8t AUQ. The second day I owned it the turbo blew due to a dodgy remap the previous owner put on himself as he was a self confessed remapper (just started to do it) (found this out a few weeks later when I spoke to him over the turbo) so it was replaced with what I believe is a K03 turbo. Now I’ve had the car remapped properly so it drives right now the boost doesn’t seem as good as it was day one. It’s apparently a stage 2 map as I’ve got upgraded coilpacks. Air filter. And bigger intercooler. No n75/sai deletes have been done but the one pipe off the Sai pump was missing on purchase. It has an awesome gti diverter valve too. My boost guage was showing around 14psi after the map and new turbo but recently it’s dropped to 10/11psi. I’ve checked all pipes and vac lines and there’s no holes or splits ect. I’ve read that my car should actually have a K03s turbo not the K03 that’s currently on it. I’m not sure if I’m right here thinking this tho. Any advice on this would be extremely useful and appreciated please. I’m confused with it all now. Pics uploaded are my current set up best I could take. The pic of the damaged and removed turbo is uploaded for reference too. 
 

thanks guys. 
paul 😜

Going off last picture, with my aging memory, think that is a K03s, don't think the K03 had the muffler on it, the bit in your left hand in photo.

 

OE turbo no: 53039880052

OEM part no: 06A145713D or F

Ah ok that’s great to know thank you I’ll look into it

Yep. stock fitment turbo on an AUQ is a K03s.