Brought this first para comment of mine over from your noise thread mate.
If CRD check that the VNT solenoid is still plugged in. CRD require it to be plugged in when Dawes/needle installed even though VNT solenoid is bypassed(vac).
Also check vac lines as you said and at idle have a look and see if the actuator rod is in the up most position (lever hitting stop). Check to see if the actuator rod lock nut has not come loose an allowed the actuator rod length to increase. If too long eng will become very laggy and exhaust will get more of a throaty sound and higher EGTs. The witness line up marks on the the adjuster thumb wheel to actuator rod will indicate any movement. Best leave it alone if looks like it has not moved.
Following up from mudski comment, with your stock IC, take it off have a good look around for any oil residue top and underneath(bottom), and especially both tanks where crimped. Of course you will have a good opportunity to check/inspect boost hoses, hot/cold sides.
Vac hoses generally 3mm and boost side 4mm, think that is correct. I had Dawes, now use Tillix (both good) but the Tillix was installed by the guy that did my tune with ECU remap, the hose supplied by Tillix was 4mm and was slightly loose on the dampener (at vac take off) and this gave me poor spool/laggy until I got onto it.
There is a way to check your VNT boost behavior by bypassing the manual boost control but caution is req'd when doing this. This is how I got onto my spool/boost problem but other investigations first.
Your Dawes - is it the "Black" body and stenciled 3 Bar Racing? _ this is the one that is proven good IMO (also was supplied by mudski):
https://dawes-devices.com/collection...patrol-and-vag
Have you got a scan tool for clearing fault codes?
There are some good comments above by the other guys so no need to repeat.
Would not hurt disconnecting battery over night, but do not think ECU/limp fault is your problem at 15psi max boost.
What gauge you using to monitor boost? Had an issue with VDO boost line brass ferrule at cooler failing and had a significant impact on boost but I run 26psi.
Before you start pulling things down run the engine at idle and gradually unwind needle from the fully closed position and see if your noise stops.