Looking for some advice here. Since I bought my truck back in March, I've been able to feel the entire truck shake a bit at idle, especially when cold. Recently as of a few days ago, I've noticed it's become a bit slugfisl when accelerating, especially between 2nd and 3rd gear around 2-3k rpm. Right before it shifts, I can feel the truck hold back a bit, and the rpms quickly drop slightly, as if I had let off the gas, then they pick back up to normal.

Could this be two separate issues, or all related?

I replaced spark plugs and coils about 20k miles ago, could they have gone bad that quick? Or is it a tranny issue?

 

What engine?

 

V8 4.7l