I am at the end of my troubleshooting stampede and the only thing I have left to check is if the ECU is wonky. Looking for someone with an ECU I can borrow to swap in, its going in an 02 so I think 02-05 will work, but correct me if im wrong here. I will of course pay shipping both ways and a tip for letting me borrow.
Sorry to hear about your :llama: Kudo to you for trying to source out the problem. Hopefully someone near by can loan you the ECU.