Reply To: 2007 silverado 6.0 running poorly when warmed up

Have you checked fuel pressure while driving (under load)? Usually if it runs bad when hot, that’s a fuel pump/regulator issue. If you’re able to read fuel trims you could see if it runs rich (coil or injector issue) or lean (fuel pump or injector issue). First i would bench test each coil if you have a multimeter (free), next hold a stethoscope (long piece of metal or screwdriver) against your ear on each injector while its running to make sure each one has a consistent clicking, if that checks out then replace the fuel filter and if that doesn’t work then its most likely fuel pump.