Highway running high Rev/low rev
 

Hi, I have an issue with my 6.5 when driving on highway the engine has a noticeable (by ear ) high rev/low Rev it's performance is fine just hear it every time ( my 13 yr old asked me what it was I had no answer...lol) you can feel it in the peddle sometimes. ......any help would be appreciated. ..I changed injector pump /pmd/boost sensor