I recently had on my new Legacy break down on me and after fixing it I have discovered that I have lost four psi in my boost, I have a gauge on the dash and it usually read at seven psi but is now down to three psi. I was told to check some vacuum hoses but I’m not sure which ones to check, any advice?

Edited September 19, 20205 yr by LegacyGT2.5L

Also, is this my only concern? Or should I be worried about some thing else being my problem.

Edited September 19, 20205 yr by LegacyGT2.5L

Should be around 12 psi. The VF40 turbo on these is a common failure as the design of the turbo oil feed was very poor. Either the turbo is bad or your have a large boost leak. The turbo is incapable of making less than 7 psi as that is the pressure at which the wastegate opens. If you are making less than 7 psi you have a huge exhaust leak, a sizable boost leak, the turbo is bad, or the wastegate is jammed open or the puck is gone. 

The 05/06 LGT platform is one of the worst for reliability and longevity if not properly maintained - they have a LOT of compound problems that take a knowledgeable expert to overcome - there's a regimen of about $6500 worth of upgrades that are usually required to get one into the right shape for reliable safe performance. 

GD