sometimes my truck runs great other times will putter or stall at low speeds.

What is your question?

During the puttering when you press gas pedal it acts like it don't want to accept it. Could this be a bad egr valve? Maybe a faulty ignition switch?

What makes this problem better or worse?

It’s just random

How long has your 2005 Chevrolet Avalanche 1500 had this problem?

A long while