Recently got a 2001 GMC 2500HD with the 6.0. When the truck is cold started and drives after cooling down it runs perfectly and has no issues driving or power related issues at all. After its warm and you re start it though it wants to die right away. You can keep it running but not happily and barely at that rate. Has some codes I got off my scanner and recently has had an EGR valve replaced. When I bought it, they gave me some top-of-the-line coil packs and plug wires with it but the coil packs on there now have been replaced in the last 6 months. I was told by a friend it could either be coil packs gone bad, or possibly a bad coolant temp sensor. Not sure if starting with the temp sensor or coil packs and wires is a good place to start or if I have a different issue I'm looking at. The current codes I have ar as follows:



PO121

PO122

PO300

PO327

PO404

PO405

P1404



Only get these codes after the truck has been warmed up as far as I'm aware, ordered a OBD scanner with live feed today and won't be 100% sure on the accuracy of that until it arrives. If anyone has experienced this or has suggestions, please let me know. Thanks, Lane.