Rough idle

[MikeC]

Got a shaky idle on my 02 RWD 3.0 L. 172k. No CEL. Rpm will dip down a bit as the car shakes, then go back to normal. It does not feel underpowered when driving. No trouble starting the car, pretty normal mpg, and no other symptoms I have noticed. Ignition coil is new(ish) - which I read commonly causes this sort of issue. Any tips or suggestions? Thank you all.

 

[RangerAl]

Clean or replace the "IDLER AIR CONTROL" (on top of the throttle body), and MASS AIR FLOW METER (after the air filter box). Spark plugs are good? Motorcraft seem to be the only choice, when replacing the plugs.

 

[DeanMk]

...AC will work, too.
+1 on cleaning the IAC and MASS air flow meter, too.
"Throttle Body Cleaner" (formerly "Carb Cleaner") will work nicely.