Pulled out the plugs to have a look-see, the all came out very easy. But something weird?!
The first two plugs, being the first on drivers side / passenger side were black-oily appearance -tacky stuff.
All the others were dry w/ brown looking dust.
Tune related?!

 

Hmm... that's a sign of too rich for those cylinders. But if it's tune related all plugs should be the same since they share the intake. I am not familiar with a tune controlling the A/F of individual cylinders.
I wonder if those 2 coils are getting weak and not firing properly?

 

Sounds like a good place to start, makes sense.

 

pictures?