I have a 2006 Evo Mr with low miles and lately been having some boosting problems.. My boost comes and goes but it never fully boosts.. Max it goes up to is 1.0 bar but most of the time its in the 0.3-0.5 bar area car is bone stock and has never been modified. Can someone please help me out and tell me what the problem is? Thank you!

 

Possible boost leak....do a boost leak test

 

^^^ This. Did you do a visual inspection? Check your clamps and make sure theyre tight and do a boost leak test.