Hello again, guys. This has been going on for a while and hasn't really affected driveability. I just want to be sure it's not a precursor to something more serious.

Every so often when idling (regular idle speed, about 800 RPM) the engine seems to "shut off" for a split second. IOW, the idle RPM will dip down slightly and then immediately rise to normal. Yesterday, the idle dipped abnormally low, almost to the point of stopping the engine but lasted only a split second and then was back to normal. This only happens occasionally but scares me into thinking that the engine may suddenly die on me.

The fuel filter had been changed a few thousand miles ago and the air filter is new. Other than the above mentioned symptoms the truck drives well. Do you think this glitch is normal or is there something that needs to be fixed or adjusted before it gets worse. No codes have been thrown and the CEL is off. Thanks in advance...

 

I think it is the EGR cycling. I don't think it's anything to worry about.