2000 GMC Jimmy 2wd 4.3L I have a very annoying problem that I can't seem to find. In the morning when the truck is cold, it is the most obvious. I start the Truck and it idles fine, perfect, no problems. When I start to take of and accelerate up to speed, it starts to sputter a little bit. Not real bad just enough to make you back off of the gas. It settles down and then I can usually give it more gas and take off. When the truck warms up it is still there, but hardly noticible. It threw a P0300 Random Misfire code once, I cleared it, and never threw another code again. I replaced the Thermostat because the dash gage seemed to be slightly cold. I also replaced the Cold Air Temp Sensor in the intake duct, cleaned the MAF Sensor, and replaced the air filter. I replaced the coolant temperature sensor too. The plugs are approximately a year old and the wires, cap, and rotor are 6 months old. Fuel Filter is brand new. Nothing has helped.