Hi all,
I'm not mechanically minded so bare with me.
I have a 2011 WRX with no mods. Car has 91k.
Recently noticed white smoke from exhaust starting 30 secs after start up, and slightly smoking there after. I also feel the car is slightly lacking boost.

A call to a dealer says he believes it be a problem with IC, and a second opinion from a mechanic suggests it to be a blown head gasket.
Is it true this is common in this vehicle and nonetheless, does the above diagnosis seem to be correct?