Help Needed fumes in cab,low power

[fordoor]

I expected leak in the Y pipe or expansion joints, but when I finally got around to hooking up my boost leak detector from Dieselsite. I found a major leak coming from the back corner of the driver side valve cover(rocker carrier cover)closest to the y-pipe. The dealer has replaced this once before when they installed new heads,gaskets,studs about 30k.miles ago. I'm wondering if I'll have any luck tightening the back few cover bolts, or do I need to remove everything and replace gasket? or is it sealant(or both)? Torque on these bolts? Anybody had this problem before?

 

[fordoor]

I just realized my mistake. I hooked the boost leak detector to the section of intake attached to the turbo and not directly to the turbo! What an amatuer! Anyway, I learned that my rocker covers can hold about 5 p.s.i. because after tightening up one side and then repressurizing.... the other cover started to leak,as well as the other side that I just tightened down. Is this right; that they only hold 5psi.? I'm going out now and hooking up leak detector directly to turbo and start over; fingers crossed! It's very tight back there around that y-pipe,expansion joints.

 

[fordoor]

I'm now confident that I have no boost leaks after fixing a couple minor boot leaks. Soapy water spray helped a lot to find them, as well as a mechanics mirror to see under them. But I still have either exhaust or crankcase smell getting into cab. I believe the dealer uses a smoke machine for this diagnoses but does anyone know a way I can find the leak myself? I was thinking of hooking up the boost leak detector to the tailpipe(cold)and pressurizing and listening for leaks. Any thoghts?