cold starts

I have an 05 F350 with 85K miles, and 10K miles on egr delete, new head gaskets and studs, new oil cooler and CAT delete. This is the first time I've had this truck in weather below 30F consistantly. For the first two months it was totally normal: a little smoke on startup, high idle kicked...

Ok I am at a loss, first of all I have done to the truck is 4" turbo back mbrp no cat no muffler, and banks 6 gun( which usually stays on 6 unless towing) recently replaced egr and fuel filters. Now for the problem.. When starting in temps that dip below 50 it'll start and sometimes cut off...