have you done a boost leak test ?
This may help.
This is a list of codes in the warranty forum on here.
the p0030 sounds like a bad front O2 they are about $100. call a lot of auto parts stores, the prices very widely.
188k, 5/20/12 new ej257 short block, 8/20/11 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. CHECK your oil, these cars use it.
Engine Build - Click Here