Popping and stuttering after Efi install and rebuid

I absolutely agree that without it adjusted properly, failure can occur. I don’t know you nor your skill and level of experience so please forgive the grilling.
I just see many people repeating things they hear without knowing nor understanding what they say. I’m guilty of that too, of course.
The original issue at hand though… I usually thought that popping in the exhaust also happens from raw fuel in the exhaust stream igniting. A misfire would send unburned fuel out the exhaust valve and maybe igniting in the manifold.