My tahoe has recently gotten a new engine and for some reason the engine shutters at low speeds and will eventually throw a stabilitrack and engine lights. When diagnosed at an electronics specialist, they said the #8 cylinder is not turning off and the problem is in the engine or head. What is making it do this and what am I looking at to fix it?

 

The problem is a half-baked AFM system. There's a vale lifter kit that will make it stop turning off cylinders. Delete AFM and the issue will go away