Mark Pile

Hi folks, I'm looking to get a blob wrx, lad says it has a couple of issues, 1st being it only boosts about half it's normal boost so I asked if tis in limp mode, he said self diagnostics says it's the boost solenoid, as it clicks only every 3 seconds and not fast like it should, easy fix really, but it also has this po558 brake servo sensor circuit high voltage, are we talking broken abs unit here or is the alternator done in, thanks in advance mark