12 psi max boost
 

My buddies 2001 powerstroke with a t.s 6 pos chip, intake, guages, 4'' exhaust, and garrett 38r turbo and it only makes 12 psi boost and cleans the smoke up and run better then my 2002 i used to have would with the only sifference being the turbo

12psi of boost is super low... A stock truck without tunes should be making more boost than that...

If the truck is running like you say it is, check the boost gauge line and see if it is kinked or cracked...

agreed. busted boost gauge? its getting air if its running like a raped ape.