It seems to be the year of CELs for me, both for evaporative emissions.
I found this excellent article on a 96 Ranger, probably identical to my 97.
http://www.tomshints.com/FordRanger/FR_EPS.htm
I read through the article, then I went out and looked at my truck. It's a fairly simple setup, the only hose that had ever been replaced was the one to the intake manifold.
The rest of the hoses were basically disintegrating? $2.63 later I had replaced all of the engine compartment hoses, except for the one that was already replaced.
The only issue was the hose from the charcoal cannister to the purge valve. In their "brilliance" Ford decided to make one end larger than the other, in fact so much larger that the ID was as big as the OD of the rest of the hose.
I had an assortment of vacuum caps from a previous repair, found one that fit the larger diameter, cut the closed end off and used it for an adaptor.
Seems to be working fine. I think I can tell a slight difference in how it runs, but it could be the placebo effect.
regards
Mech