I drive a 2000 Chev Crewcab K2500 5.7 4W. The engine is a GM rebuilt that I had installed 100,000 kms ago. The odometer reads 285,000. Last summer the truck would simply die. A friend changed my distributor, crankshaft and camshaft sensors, and the fuel pump. It improved but still the odd dying. Okay during winter. Mild weather is back and it's doing the same thing. Once it warms up, it dies or if I turn it off it won't start again. The DTC says no codes but the I/M says O2S, HO2S and EGR are 'not ready'. If I erase the codes it may restart. Sometimes, I have to disconnect and reconnect the two top cables on the ECU to restart or I have to let the truck cool off to allow it to restart. I'm at a loss and don't know how to resolve this problem. I hate to change the sensors, ECU, CAT only to find out it hasn't been solved. Can anyone help?

 

get it hot so it fails then start testing the basics...fuel pressure..spark

 

maybe your o2 sensor is overheating causing your bcm to think truck is overheating? I would start with new o2 sensors and clean out egr valve. thats an affordable attempt at fixing your problem before overpaying some shop to do it.