Question

2001 Chevrolet Tahoe 5.3L with code P0300, engine runs smooth, good acceleration, starts fine

Answer 1

I suggest starting by inspecting or replacing the spark plugs, if the plugs are OK the next step is to check the injectors. Even is your Tahoe is running OK, at some point the engine may have a cylinder misfire, but it's not bad enough for you to feel it.

P0300 CHEVROLET - Cylinder Misfire Detected Random Cylinders
Read more: https://www.autocodes.com/p0300_chevrolet.html