My truck has been running great for the lasts 2 years. Today is actually the 2 year anniversary of me buying the truck. Still have great power and rumbles great down the road with no lights or anything.

Lately though at stop lights my idle will be inconstant. Will either sit smooth at about 550rpm, or be high but smooth around 700, OR that one that worries me the most is it will idle at 550rpm then drop down to 450 or so then catch itself and go back to 550, then drop back down.

It has the usual maintenance, new spark plugs around 100k, oil change and air filter just a few weeks ago, so this idle has me a bit puzzled. Maybe time for a new fuel filter? MAF sensor dirty?

Any information is helpful, for some reason I am just stumped

 

Often, cleaning the throttle body and MAF sensor solve the issue you describe. Lots of threads and U-tube stuff on "how to".

 

IAC valve?

 

did you find your fix?

 

These engines are DBW and thus don't have one.