Currently at 240k miles. A few months back I repaired the fuel pump, fuel lines, alternator and both batteries. It’s been running fine until this past weekend while loading the truck while running it just shut off. I cranked it again and it ran fine for about 10 seconds then started idling really rough and check engine light came on. I did this a few times and the same thing. After sitting for a few hours I went back out to move it back onto the driveway and it ran fine. So I was thinking possibly it’s the valve cover gaskets? I’ve pulled the plugs on both sides and on the drivers side I have some oil in the plugs***I also pulled the plug that had oil while the truck was running rough and it didn’t change anything. I’ve read around online and I’m thinking this is the source. What else could be a possibility I know there are a few sensors but I’m not sure of the symptoms each would show. Thanks for any feedback.