hi all, jus developed another problem in my my92 wrx, when the boost reaches jus below 0.5bar, it stops giving it and theres a loud continuous whoosh sort of noise, sorta like a dump valve noise but continuous and whilst im still in gear, coming from the engine. ive checked the hoses and cant seem to find the prob. anybody know what it is and how to fix it?

p.s. gettin the heat shield prob fixed this week, thanks for the replies