Forgive me if this has already been addressed for the 2021+ forum, but I wasn’t able to find anything when searching.

My family and I took a trip from Denver to San Antonio and after filling up with 93, our idle in drive sits around 500. I have a little PTSD from when we had coil pack and spark issues late last year, so feel like I’m waiting for it to happen again.

Conditions: 90+ degrees, high humidity, A/C running (most of the time). Oil pressure good, temps all good. Still had a little under a 1/4th of a tank left of 91 left before I filled up with 93, so not sure if that matters.

Truck runs smooth and seems to be driving normal from what I can tell, aside from the low idle. When put into park the idle “normalizes” at 700 RPM.

I haven’t had the time to check the throttle body or anything, but with only 19,000 miles I wouldn’t think it would be that dirty, right? I was thinking it’s a fuel thing going on.

Anyone have any tips or experienced this for themselves?

 

500 or just over it seems normal to me once warm. But what do I know. I drive a V8...

 

I reckon I have nothing to worry about, but the idle was always 600 RPMs in drive since we bought new, until now.

 

There is a procedure to recalibrate the Throttle body.
Have that done next to see if it makes any difference.
No parts, nothing to take apart, done from inside the cab as a control procedure.
Good luck.

 

Is this a dealership procedure, or something I can do? I’m not familiar with how this is done.

 

Here's another explanation: How to Perform Ford Idle Relearn | MPT Performance (morepowertuning.com)

 

I wonder if it could be an automatic ECU adjustment, when you changed both octane and altitude. See what happens after you get home.

 

I was thinking that as well.

 

If you have access to a scan tool (Forscan may work too) I would clean the throttle body and hook up a scanner check for any codes in the PCM if none I'd reset the Keep Alive Memory.

 

So I have noticed with my 23 3.5L eco, with 500 miles on it now, it sometimes shows the idle at 0.5 when sitting at a light, other times it will be 0.6. Everything seems to be just fine so I am thinking the threshold for where it shows 0.5 or 0.6 is a fine line maybe.