I recently bought an 04 suburban. While driving it will go into limp mode and return to normal driving several times then drive normally for 2-3 weeks. It either stops on it's own or when the truck is shut off. I have been looking for the grounds and cleaning them and I'm about to take it to the chevy garage as soon as I figure which one I think will best suit working on it. I'm curious as to what is causing the issues. I have no check engine codes, I changed the plugs and wires recently hoping, everything looks good when I have it on the lift. I'm baffled. Any ideas.