majority of problems on 2.5 cars are on tuned cars , mine ran like clockwork until i fooked around mapping it , the headstuds seem to not be up to the task of holding the heads down when boost is increased giving the appearance of hg failure , mine would appear to have been starting to overheat after a spirited drive , under normal driving there was never an issue , and everything was normal ,
but i decided to send her up to ali to replace the known week points , head studs, gaskets etc and while the engine was out i said change the pistons to be sure to avoid ringland failure , even though the standard pistons were looking fine at that time , the piston issue was more well known on the hatch than hawk according to all i have read on the issue , the wrx motor been under less pressure than the sti motor didnt suffer as badly but there has been reports on other sites of some wrxs failing , including a few gb270s ,