99 dodge RAM 3500 4x4 69,000 original miles 5 inch tbe airdog 150 edge juice with attitude CTS all new in the last month or so now my rpms seem to be fluctuating at idle not horable but from 861 to 890 and I have a vibration you can feel threw the seat and steering wheel its only at idle you can feel it . ??? I'm lost

 

Any codes?

 

No codes but fuel pressure seems to be jumping around from 15 to 19 sometimes it runs 15 sometimes 19

 

No