Hello, I have an audi a6 2.7t..car is shuddering at idle and under load..car is throwing p0102 MAF air, and a p300 cyl 2 misfire..checked all vac houses/connections everywhere..no leaks. The vac house Up by the drivers side diverted valve where it connects to the hard line by the throttle body is making an extremely loud hissing sound..(seems like it is overpressurized)there are no leaks however and the other dv side is quiet? What gives? Only thing I can think of is the drivers side turbo is seized up..

The other day it started shuddering under load, then suddenly smoothed out..only to have returned later

Any ideas guys?