I'm currently looking at a 2004.5 h.o. with 190k that seems to have just one problem that I could tell. The thing started and ran great for the the first 5-10mins then started running real rough almost like it had a lope. It smoothed out with any increase in rpms and was normal at highway speeds and such. He had the injectors tested and they all checked out. I'm thinking it's something electrical but want to know what everyone else thinks. Just don't want to buy someone else's problem.

 

Hard to guess but fuel related. Any codes any programmers?

 

The current owner claims it's never had one and that's something I was looking for as I know they can ruin a pickup if not used properly. He bought it with 160k there had apparently to his knowledge never been one. There was a check engine light on but claimed it wasn't before he started unpluging connections to see if he could solve it. Would flashing the ecu or putting a chip on it possibly solve the problem or maybe a pressure relief valve