My father has a 97TD, and here is the problems we are having. Towing a motorcycle trailer out west, it was fine about half the trip there, then whenever it would go into any gear other than OD, the truck would rev up correctly, but would lose speed. Thought it had something to do with the load, but it also does the same thing with no load. If going about 55 mph, and slowly get into the gas to keep it in high gear, it will accelerate correctly, but as soon as the truck drops a gear, it revs up, and begins to actually slow down. What could this be? I've looked a bit over the forums, but I am not familiar with this truck, so I'm not exactly sure what we should be looking for.

pj

Welcome to the site visit welcome notes and update signauture line so we know what truck configuration is, also swing by FAQs; from initial summary you present I suspect a wastegate problem, or something in fuel delivery from lift pump, need more info go thru FAQs and see if anything there rings true. Then come back with more info, go by autozone or similar to see what code you are throwing, what color smoke you getting when loaded, a lot or a little

Check your supply pressure on the fuel filter bleed at idle. I'd suspect low pressure or a restriction on fuel supply (filter,OPS, LP). The code you're getting could be "limp mode" as well, which would be CPS or optical.