Guys...it's a pressure SIGNAL. the size of the hose does not make one iota of differance, as there is no flow in the wastegate system. the hose should be 4mm internal dia, but it would work just the same with a 1mm internal dia or a 30mm dia.

don't worry about it, and don't waste your time change vac hoses and taking the signal source from other places. the bov line is fine, probobly ideal even.

it's probobly just a sticky gate and needs to be moved a few times...burr on the shaft or something.

 

I drilled and tapped the lower half of the ic pipe between FMIC and throttle body for the AEM ait sensor. FYI it's thick enough to tap and get a few threads. but don't bother, that's not the problem.