slight miss in the passanger side exhaust and gets really low gas milage? on 2006 Ford F-250 Super Duty

It has the miss all the time while idling and has always gotten low gas milage

any codes?
No check engine light isn't on
probably going to be a bad coil. can disconnect coils one at a time, see which one does not change how engine runs. probably best to take to a shop for diag.
Alright thank ya