I was wondering if your subaru still running? did you have to replace the engine like other members mentioned? or have a "catostrophic failure" ?
I have a 2004 Subaru sti, which have the symptons you had on your car.within 1 week i had to replace 2 turbos, and after a month the 3rd it seems going bad. starts with a "sneezing of the engine" as seen on the youtube video [http://www.youtube.com/watch?v=YpOZTh8AVUY]
and also the P0021 codes. thanks for your help and your time.