2001 tdi 255,000 km. power loss intermintent, sometimes can run for 50 km before problem, sometimesw less then 1 km. fault code over boost. mechanic stated that the turbo is clogged-carbon build-up-should replace.another mechanic said that the intake manifold is possibly clogged and we should try that first. turning the key off and on solves the problem temp-replaced the solenoids n75, n45? and the maf. now going through the posts.