2001 Chevy extreme blazer problems

my blazer is making a funny sound ,and it has a miss when i have one of the sparkplug wire is on ,but when i take it off it sound alittle better and run alittle better But my blazer never sounded this way
can some one please help me:frown:

Welcome to AF.

We need more info.
How many miles and what engine?
Describe the noise as best as you can?

What have you done so far or not done?

Have you been crossing the plug wires?