Is your boost gauge installed right? (No offense)
Hks bov is main reason you are getting lean and rich codes... along with the TBE.
Is the TBE catless? If so thats why your rear o2 sensor is out.
If i were you i would put the stock or an aftermarket Bypass valve back on, then i would either change or pull the rear o2 and buy an Ap or get a tune to eliminate the codes.
Is the up-pipe still the stock catted up-pipe? If so change that immediately so you wont have to buy a Turbo along with the other stuff.
I hope this helps out somewhat. I went through the same except for the boost gauge, and i bought a new up-pipe, crosspipe and a Cobb Ap and it fixed everything. Good luck