Ok I got a 2002 Silverado 2500 with the 6.0, 260,000 miles on it and it's idling rough and will die when i let of the throttle.

Within the last 10,000 miles plug and wires both was changed. I recently took
my truck to the shop to have them fix it, they changed knock sensors, fuel
pump, and fuel pressure regulator. Still didn't fix it. The check engine light will
come one the later shut off. When it's on it runs really rough while at idle, but
when I give it a little gas it runs fine. When the light is off it will run fine. Any
help be great. Thanks.