Misfiring or something

Truck is sluggush between 45/50 miles per hr…1999

You really don’t give much to go on. Have you checked anything? hows the gas mileage been,steady or have you seen a significant decline? what about maintiance history?

And miles, and condition, and engine, and transmisison, and how is it above 50?

I’d suspect the ignition coils that sit on top of each spark plug. Perhaps one or more of them are going bad on you. Pretty common problem on Ford engines.

And what kind of truck are you talking about?

f-150 1999 V6 4.6 130000 miles No light showing on dash