6.0 no boost and exhaust leak

I'm posting this for a buddie of mine. He has a 05 6.0 he just replaced head gaskets and did a egr delete. After he got it all back together we fired the truck up and noticed a exsaust leak by the y pipe also his turbo is not building boost. Any ideas ? I'm wondering if the exsaust leak is causing the issue also the truck has a edge programmer