Well the truck finally ran bad enough that I decided to do something about it. Engine code showed cylinder 1 misfire. Short version of story ripped down top end. New head gaskets and heads. Got it all put back togather but still has same little miss in the engine. Then the engine ran terrible and would stall out. Unhooked mafs and the engine ran fine. Put a new mafs in and ran ok for maybe 20 min then when you rev it up it stalls out. Unhook the mafs revs fine. It still always has just a little miss in the engine but won't throw any codes. Any ideas why when unhooking the mafs it runs ok.