shaking while in gear

[jarhead2010]

after my truck was warmed up i noticed a lot of shaking while in gear..and a very throaty noise. it only happens while the truck is in gear regardless of if im moving? could it be my idle? didnt throw any codes...any suggestions much appreciated
99 3.0l ff auto 4x4 106000 miles

 

[Bent Bolt]

Engine missfire.

 

[jarhead2010]

Wouldnt that throw a code? i put some seafoam in my tank to see if it will help