Harmonic dron from exaust at 45 to 55mph

[RDeGroot]

Recently truck was starting hard (long start time) dealer replaced lift pump didn’t fix, replaced fuel pump didn’t fix, changed two injectors problem fixed. After repairs the 55 mph Harmonic drone started and the warranty is up. Truck has 110 thousand miles. after market parts include Banks intake and MBRP dule exaust. The exaust is new after problem existed. Any insight on where I should start to cure the pulsating drone.

 

[K5IP]

Does the drone remain if you take it out of gear and let the engine idle while coasting through the 55-45 mph range?

This should help identify the problem as being engine or drive line related.

Rog