I thought the stock boost setting was at 13.5 (highest) for the WRX. My boost gauge last night would spike up to 15 around the 5500RPM mark. Is this just a gauge error, or could the previous owner have put in a boost controller without the dealership knowing?? I bought the car slightly used. The girl had it for about 2 months, and lost her job so she sold it back to the dealership.