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Discussion Starter · #1 ·
I had to share a experience i had with my 35k mile 2016 ST, buddie and I drove across Washington to pick up the ST in Seattle I let him drive the ST the 5 hours back to town.
He filled it with 87 and still half a tank left I filled it rest up with 92 and added some octane booster I flashed a 91 tune and did a relearn, after that tank went empty i filled with 92 again.
Shortly down road started misfiring like crazy felt like I was driving down a gravel road, scanned it and it showed just shy of 130 misfires before i got to a place i could pop hood.
No check engine light, no missing coolant, oil was fine, Fuel pressure fine (just had one st
Tire Wheel Car Vehicle Window

that high pressure system failed on highway and cracked head) I was about to give up. I reflashed stock tune, went to buddies shop did the full reset and relearn and guess there's a procedure for relearning the misfire correction where you rev it up 2000 let it drop off then 3000, 4000, 5000 so on. Now car is running great again. Wanted to get that note out if you change your fuel type do a complete relearn.
 

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2014 ST3. Garrett GTX2860R Gen 2. FBO
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So, not trying to poke holes in your story here, but i'm not quite following. You mentioned you actually felt the car shudder, which is an actual misfire. So the car was properly reporting said misfire.

This is the first I've heard of some sort of reset for the ST (possibly a crank/cam learn? I'd like to know the actual step by step procedure to this, out of curiosity). Typically this type of reset will alleviate false misfire codes, from my personal experience repairing other platforms of vehicles. Meaning, the engine is not misfiring but the computer is counting misfires. You experienced and actual misfire, though.
 

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So, not trying to poke holes in your story here, but i'm not quite following. You mentioned you actually felt the car shudder, which is an actual misfire. So the car was properly reporting said misfire.

This is the first I've heard of some sort of reset for the ST (possibly a crank/cam learn? I'd like to know the actual step by step procedure to this, out of curiosity). Typically this type of reset will alleviate false misfire codes, from my personal experience repairing other platforms of vehicles. Meaning, the engine is not misfiring but the computer is counting misfires. You experienced and actual misfire, though.
That relearn procedure is something that they advise with the FRPP tune from what I remember - in ProCal3 its called "profile learning", and basically not recommended unless you're having performance problems. It forces the ECU to relearn the firing sequence, I believe. Something I wouldn't have done myself, personally, as I feel it just masks the real issue.

Reference to what I'm talking about on Page 6:

Microsoft Word - ProCal 3 User Manual 8-2-2016 (2) (ford.com)

The other half of the issue probably would be the half tank of 87 octane. Even if you used an octane booster, that'll cause issues. Octane boosters alone cause issues and will foul the internals of the engine with a nice orange residue.

OP - what tune are you running, anyway?
 

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Thanks for sharing that, storing that away for a rainy day.
 

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From the linked manual:

"When to use Octane Adjust and Profile Learning

The Octane Adjust switch should only be switched to “ON” when spark retardation is desired. Some engines have increased octane sensitivity and require spark table adjustment. By switching the Ocatne Adjust switch to “ON” you are telling the PCM to reference a different spark table. Normally, this is only necessary if your engine is knocking. The Profile Learning switch should only be switched to “ON” when the engine is reporting a misfire DTC such as P0300-P0316. By enabling this switch, the engine will prompt the driver to rev the engine to a specific rpm until the PCM relearns the fire pattern characteristics of the trigger wheel."
 

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From the linked manual:

"When to use Octane Adjust and Profile Learning

The Octane Adjust switch should only be switched to “ON” when spark retardation is desired. Some engines have increased octane sensitivity and require spark table adjustment. By switching the Ocatne Adjust switch to “ON” you are telling the PCM to reference a different spark table. Normally, this is only necessary if your engine is knocking. The Profile Learning switch should only be switched to “ON” when the engine is reporting a misfire DTC such as P0300-P0316. By enabling this switch, the engine will prompt the driver to rev the engine to a specific rpm until the PCM relearns the fire pattern characteristics of the trigger wheel."
Bear in mind, this is for the FRPP calibration - but it probably applies to regular diagnostic that they do for OEM setups. I would realistically think that with other tunes, checking plugs, gap, and cleanliness would be a first step.
 

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Discussion Starter · #7 ·
To first response it was shaking and my tuner was just going up in misfires at a consistent pace like it was missing every 1-3 rotations.
It was Ford OEM diagnostic stuff that they were using.
No the car hasnt thrown a single code or have any pending codes even when it ran like a jalopy.
But I have a question has anyone observed a exhaust note that sounds like a sputter or puuuh like a cough uneven with the rest?
 
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