'99 Yukon 5.7
After doing all the obvious tune up stuff, TPS and Crank sensors the light
throttle misfire was caused by the distributor.
Symptom was a light throttle cruise miss at 1500 rpm, idle smooth and WFO
ran like a champ.
Miss triggered P0300, P0307 codes and a #2 cylinder miss history.
New distributor was the cure.