ok i have a 2000 cummins it runns good and idles perfect:thumbup2: but when im crusing and just in the throttle just enough to maintain speed it raddles up a storm almost sounds like a little jackhammer:neutral: it goes away when i release the trottle it also goes away if i hammer down:woot: but then i get what sounds like a random pop comming through the stack:stuned: i have adjusted the valves and checked all that i can think of:banghead: does anyone have any suggestions as to what it could be