Have a few questions on a 2004 Passat 1.8t AWM engine

I normally drive an 02 TDI Jetta, but recently bid on an online auction for a 2004 Passat with AWM 1.8t gas engine.
It was advertised as running, driving, stopping condition. Got it for $750.00 which i thought was great. Drove to Phoenix to pick it up and it had a bad miss at idle which dissapears when you give it gas.

I have ross tech Vag Com that i use with my TDI so i hooked it up and measured blocks showing misses in the engine and there were several on each cylinder.
This led me to believe that the coilpacks where probably bad so i went and got brand new NGK plugs and coilpacks, installed them, and then it popped a code for
Pressure Drop between Turbo and Throttle Valve (check D.V.!)

This led me to the diverter valve. Found it and then clamped off the small hose with channel locks - started car and idle was still rough. Unclamped the channel locks and nothing changed on the idle so i am under the assumption now that the diverter valve probably isnt the problem.

Next i got my mapp gas torch and passed it around every hose i could find looking for a vacuum leak and the engine never changed idle with the torch head anywhere near any hose.

The only thing i can physically see is this 90 degree fitting is cracked. What is this, what does it do, and will this cause bad idle?

Thanks in advance for any help

Anthony