I have a 1999.5 7.3 that is randomly throwing a SES light, I took it to Advance Auto to have them use a code scanner on it (Not the best place to go) and tried a few different times but nothing. the SES light only comes on when the truck has been running for a while and is warm. When I turn it off and turn it back on when it's warm it comes back on after 5 seconds or so. I recently 300-400 miles ago installed a WW2 also a intake heater delete and afe intake all in the same day so I had my engine apart but it wasn't throwing any lights till recently. Any help or suggestions would be helpful. I unplugged my HPOP during the process and valve cover harness. Another note my hoop might have a slight oil leak. also the truck seems to run a little rough but my oil pressure is high from what I can tell.