The check engine light comes on from time to time

OK, thanks. Do I need to go to a Ford dealer for this, or do independent shops usually have the instruments to do the diagnosis and repair?

A good independent shop (along with a good tech) will have the tooling and expertise, as well as a dealership. Funny enough - it's getting harder to find more mature pros who remember the function and operation of a 21 year old truck...even at a dealership (i'm not entirely sure about Novato Ford - nearest to you). So definitely look well and make sure you have a good place you trust.

Thanks Dave, I appreciate your help. I'll call Novato Ford and a couple other shops I like to see what they can offer. By the way, my truck is 21 years old, but only has 100, 000 miles. I take good care of it and plan to keep it a while longer.

The age of the vehicle comment refers to more of the progressive skill of technicians today. Many of today's techs can be entirely competent with a 2010 vehicle, but if you give them a 1990 - they are lost. It's a different diagnostic architecture, and there are fundemental differences in operation. Consider that most of todays engines are overhead cam engines, and this is an old fashioned big block push rod engine. Many technicians today don't have any idea what a MAP sensor is or does, for example, and you have one. I think the truck is probably fantastic - low miles, nice engine -- just need a little help getting it restored to proper working order.