I have a 2004.5 With 95000 miles. I've been running a holly blue for a LP for about a year and a half. Edge juice with Attitude for about 2 yrs. Fuel filter has been changed, Power service has been tried, edge has been removed, no change, and I'm not looking for warranty to cover anything. I would just like the truck to run better. As long as there is any kind of load on the motor it idles and runs fine pulls strong all the way to the top end. Even at an idle in drive everything is good. If I idle in neutral it sound like it's got a miss. I can raise the RPM's and again it sounds like hit and miss. kind of a aaahhh ah ahh ahhh instead of a steady aaaaahhhhhhhh. Also takes a few seconds to idle down. I've also notices a little more smoke on takeoff than usual. Any suggestions are appreciated.

 

Could be an injector sticking.