P0171 Silverado 2009 V8 1500

What is your question?

Hi, Thanks for the P0171 explanation. Another problem that trips this code is a slow reacting fuel gauge? The fuel alarm on the gauge reads almost empty upon starting. I believe this was a known problem, and that the fuel level measuring device in the fuel tank was replaced under warranty. I bought the truck as used a few weeks ago. The analog fuel gauge slowly responds to the engine running and does finally indicate a true fuel level. But the P Code alarm can appear once the truck is being driven especially up a steep hill. I suppose putting more fuel in the tank may avoid these possible causes?