Clean the EGR valve, then use the ford recomended fuel additive, Yes I know that I do not like using additives either, BUT SINCE i started using the ford fuel additive I have had no problems with the EGR valve sticking. 40,000 on a 05 exursinon.
AFE INTAKE, MBRP SS Exhaust, Diablo sport in tow tune.
12 mpg towing 10,00lb @ 75 mph
No tow 17mpg and thats with me racing everybody that lines up to me, it is a 8000 lb truck!!

I leave everbody in a cloud of smoke!!