1996 Ford Windstar ruff running

1996 Ford Windstar 6 cyl 220000 miles

when starting the van, it seems to run ok untell it gets warm (normal operating temp) then runs ruff and a miss, no power run, no engine light. New mass air flow senser, scan revels low flow in egr, open rails, miss in number 3, o2 bad. I have removed the intake manifold and clean the rails with carb cleaner. No difference