Bullitt 2019 - 5000 km - P0302

[akbullitt]

Hi all,
Just bought a 2019 Bullitt, 5000 km. After the purchase and short drive I've got check engine light and I did the following:

• Full maintanance service - oil change, engine flush, new spark plugs, filters, etc.
• Reset PCM (KAM reset), started with a proper adaptive drive cycle
• Monitored everything via FORScan + OBDLink EX

Problem:

• Repeated misfire on cylinder 2 (P0302), no other codes
• Happens mostly under acceleration from ~2500 rpm and up
• Check engine light flashes, sometimes stays on after a long drive
• Occasional jerking, uneven power delivery under load
• After resetting PCM adaptations, P0302 returns within a few km

What’s already done :

• Compression tested: 17.6–18.2 bar across all cylinders
• Swapped coils → misfire still only on cylinder 2

Forscan (after KAM reset + adaptation drive):

• NUM_MISFIRE >0 most of the time, sometimes hundreds in a single sample
• STFT stuck at 99.22% – ECU trying to fix the mixture and failing
• MAF and IMRC seem OK electrically
• Occasionally I see asymmetry in IMRC voltages (IMRC1M vs IMRC2M), mostly on the bank with cylinder 2

My best guesses (not a mechanic):

• Faulty injector on cylinder 2
• Mechanical failure or stuck IMRC flap to cylinder 2
• Broken IMRC mechanism or mixture issue on that one cylinder
• Small intake manifold leak near cylinder 2?

What you guys think about it? It's just 5k km - strange.
I will be greatful for any help.
I've attached FORSCAN file if you want to check it.
Thanks.

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[Rebmo]

How fresh is the fuel? Could an injector be having issues with gunk? I just bought a 2020 this spring with 700 mi on it and luckily zero issues. I did run down the fuel after delivery on the way home and added fresh. Luckily the PO must have used fuel conditioner. Fuel gunking was a big concern of mine having the low miles on it and sitting a lot for 5 years.
I’m not a big fan of fuel conditioners but maybe a Ford approved Fuel cleaner and see if the fuel path on injector 2 clears. It can’t hurt, and probably a good idea anyway having the low miles. Fuel had to be getting sour if no conditioner added. Then of course get fresh proper octane fuel in the tank.

 

[akbullitt]

Fresh fuel, I drove through like 150L since I've bought it, added Liqui Moly Injection Reiniger as well.

 

[Skye]

Recent purchase. New to you car.

You mentioned forsCAN. Does this car have an aftermarket tune? Or stock tune only?

Are there any physical modifications to the drivetrain?

Six years, 5000km. Was there any history given at purchase?

 

[akbullitt]

It's 100% stock, history confirmed with dealership, nothing to worry about it.

 

[Rebmo]

Btw, congrats on the Bullitt. Once you get this issue resolved you’ll love it.

 

[Skye]

https://www.mustang6g.com/forums/threads/tsb-22-2464-engine-misfire-completed-by-dealership.201738/

https://static.nhtsa.gov/odi/tsbs/2023/MC-10230769-0001.pdf

https://www.google.com/search?q=p03...cAoAeuDbIHALgHAMIHAMgHAA&sclient=gws-wiz-serp

We have quite a few mis-fire threads, some of them quite detailed.

One of the threads was interesting to me: it's from 2022 and involves a TSB.

While that OP had several misfire codes, with no other problems, re-flashing the PCM fixed his issue.

I realize you've got a 2019, but it's something. I wonder what affect, if any, re-flashing would have.

 

[DRIVEN]

Is there a leak in the egr system anywhere?

 

[NGOT8R]

Consider locking out the IMRCs And turning them off in FORScan, if possible. I locked mine out on my 2019 Bullitt to declutter the engine bay around the intake and provide easier access to the top bolts on the transmission. When I removed and inspected the parts, I noticed the square portion of the actuator that controls the IMRC rods was becoming rounded. I see this as an potential point of failure once they become completely rounded.

https://www.mustang6g.com/forums/threads/possibly-broken-imrc-shaft.183221/#post-3690056

https://www.mustang6g.com/forums/threads/mmr-cmcv-imrc-lockout-kit-for-gt350-im.180782/#post-4167521

 

[Leigh_bullitt]

Before you throw any money at it.
Do a crank relearn with FORScan.

 

[Leigh_bullitt]

You didn’t mention before but did you swap spark plug as well as the coil ??

 

[Leigh_bullitt]

Also one last thing…..
Take the Num of misfires on FORScan with a pinch of salt…
My car car running perfectly and I’ll still log 50-60 misfires during a drive cycle. It will sometimes log knock as a misfire as well.

 

[akbullitt]

Thank you all guys, I've done crank relearn and (again) PCM reset, also swaped spark plugs and coils once more, sprayed all the connecetors with contact cleaner. I think that crank relearn was the game changer.
Just had a 100km drive (adaptation + hard drive) - no check engine light, less than 70 misfires counted.
I am very greatful to all of you.

 

[Leigh_bullitt]

No worries mate.
Keep an eye on it and remember take the number of misfires on FORScan with a pinch of salt. It’s not 100% accurate but the knock sensors can be very sensitive.

 

[Esset]

KAM reset and crank relearn are 2 separate things? Whats procedure for crank relearn in forscan? Just curious for future usage

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