2019 5.0 flex fuel issue
 

I have been fighting a problem with my truck for years and have not been able to find a solution so I figured I would ask here. My truck is a 2019 5.0 with 45K miles on it. I have an issue when I fill up with 87 my truck pings. It can be mild or severe enough to worry me. It happens at multiple fuel stations so I know it's not the fuel. Drygas, heet and seafoam have no effect so I doubt it's water in the fuel. The only way I have found to correct it is to do a full reset of the computer using forscan. After the reset it runs perfect until I fill up again. It also shows anywhere from 60 to 85% ethanol when I'm having the issue. After reset it shows around 10% for the rest of the tank. I have no issue running 93 fuel but that gets expensive after a while. I did replace the spark plugs with a set of NGK LTR6AHX plugs upon suggestions from other forums but it's still acting up. I can't figure out what is making it think I have high ethanol content but reads properly after I reset the PCM. It does seem to be more forgiving of 87 when it's colder out but summer is coming and it's starting to act up again. Short of bringing it in to the dealer, does anyone have any suggestions I can try? I have thought about having the dealer flash the newest calibration to the computer but I'm not even sure if there is an updated version to try.

Having run E10, E15 and E85 pump gas and seeing what the Long Term Fuel Trims do to both banks and fuel injection, I would take a look at those Tables to see which way they shifted as the first clue to what might be happening.
If you find them shifted Negative 15% or more, there is a reason why and may be causing the Ping from the fuel being to lean.
The front Ox Sensors should keep these tables near Zero or with in 10% either way.
Also involved with this is the Knock Sensor to retard Ignition Timing when it detects Block and head Ringing.
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If you fueled with more than 10% Eth in the Gas, the Ox Sensors detect the extra Ox and cause the Fuel tables to go Richer to account for the excess Ox and is a normal system reactions.
The Eth % you see is a calculation and not from any specific dedicated Sensor.
There is a range and time involved when filling the tank from less than 1/4.
It is described in a Ford DOC called OBDII overview for Gas engines, in the fueling section.
The PCM makes a decision on how to treat the fuel tables based on enough time and fuel level from opening the Tank to put fuel in because it cannot be done instantly but by the Ox Sensor signals the PCM gets during combustion to know what the Gas contains, causing the extra oxygen. Then it slowly auto adjusts the tables.
When you reboot the PCM it always begins with a Gas setting and Fuel Tables Zero centered. That's the change you see, when you do it.
What your looking for in the live data is whet is out of normal limits, and what fault might is causing it.
Is it faulty Ox correction operation, Sensors, faulty Knock Sensor, air leak in the Exhaust system near the Ox Sensor, wrong Sensor, low fuel pressure etc.
Anything that is causing undesirable fuel tables to shift Lean. It may even be the fuel available in your area that would have some commonality..
Do the detective work then chase what's doing it.
Good luck.
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does it ping continually or stop after awhile?

generally just under load.

So my 2019 was making all kinds of pinging at 1500-2000 rpm.. It made this noise using every single octane level I have access to (87, 88, 91, 93 and e85)
It was enough for me to take it into ford.. They found my engine was low on oil and immediately put my truck into the oil consumption protocol.
TSB (ECM updated to newest version of software available) preformed and new dipstick with a fresh oil change.
Funny enough not only does my truck burn considerably less oil (down 1/4q after 1k miles next check at 3k) that noise was I was hearing is completely gone..
With that said I have only been using e85 because wow truck runs so well on it.
Are the two related? Probably not but I had to mention it because well it helped my truck a metric ton.
On top of all that my transmission started shifting like a dream (I assume they reset the learning thing but not confirmed)

I just went to reset the PCM and it had a learned ethanol of 26%. Reset everything and ran it and it went back to 9.8%. I am also I believe 5 or 6 revisions old on the PCM software according to forscan. I think I'm going to just bring it down to the dealer for an update. I can't wait to see what this will cost me.

Good for you. I would use E85 but the nearest station is 36 miles away. I did use 5 tankfuls and liked it,

I just updated my PCM with Forscan. I'll be honest, the pucker factor during that update was high. I will run a couple tanks of 87 through it and see what happens. E85 is not really available in my area.

I used 93 ? I use 87 all the time now.

I also only use 93. The third Gen coyote has a high compression than the previous versions. High compression engines need high octane. Since I switched never have any knocks and great performance