If there is a wire connected, it may be a fuel pump, if it just has a fuel line in and a fuel line out, sounds like a filter. I don't know much about those trucks, but I do know filters and pumps. A plugged filter will seriously impair performance. A picture might help clarify. Good luck. If it is a filter, you can most likely get a replacement inline filter at your favorite auto/truck parts dealer. Just remove the old one first. You might be able to replace the filter housing totally if not able to get a new element.