MIL on/P0302 Misfire - 2025 Maverick 2.0 EB

[mwelby]

Follow up: Drove the Maverick back from the dealer. Everything seems to be working normally.

Repair order contains standard (I assume) diagnostic procedure: verified CEL, verified misfire no.2 cylinder, performed "injector flow test", injectors passed, removed no.2 spark plug and found, "strap (ground electrode?) on plug was melted. Tech test drove the vehicle and still detected engine misfire with something called an FDRS (Ford Diagnostic Repair Scope?) and found no.4 cylinder was also misfiring. He then removed the other 3 plugs, replacing no.4 and verifying that 1 and 3 were ok.

That's what I have got right now. Two warranty spark plugs and have a nice day.

Speculation: Being old...the only stuff I remember causing spark plug ground electrodes to "melt" would be some sort of serious detonation or pre-ignition condition. I'm unsure if too much turbo boost or something like that might also cause those kind of pressures? Surely, the FORD engine control programming must have some sort of fault detection parameters for this, stuck waste gate etc? This is definitely out of my area of competence.

I have been running regular 87 octane gas in the Maverick this winter, as opposed to the 93 premium I was using over the summer. But, I can't be the only 2025+ Ecoboost owner to run regular gas, am I? In any event, on the way home I stopped at Sunoco and filled up with 93, hi just in case. I will keep you all posted on any further developments.

Yep - stick to premium.

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[mwelby]

What was I thinking - Sunoco is indeed Top Tier. If they had a station out here I would get a fill up as penance! Thanks for the correction.

Yes, they are not top tier.

 

[john21161]

Yes, they are not top tier.

Actually, where I live Sunoco IS rated as Top Tier.

This may not be the case elsewhere.

 

[mwelby]

Actually, where I live Sunoco IS rated as Top Tier.

This may not be the case elsewhere.

Just watched a video on the top and the bottom gases and Sunoco is one of the three worst at the bottom. Hmmmm……

 

[MavStangVa]

Just watched a video on the top and the bottom gases and Sunoco is one of the three worst at the bottom. Hmmmm……

Please check page 12 of the Top Tier gas brands. To Tier is an official designation not a Youtube video opinion. I don't use Sunoco because I don't have 1 near me but it IS indeed a top tier.
https://www.toptiergas.com/gasoline-brands/
Also note that NO WHERE in my manual for 2024, 2025 may be different, does it say to use 93 octane. Personally I don;t care if you choose to use rocket fuel but 93 is not required nor recommended by Ford. I run 87 in the Maverick as I did in the 2014 F150 for 165k miles, 2023 turbo SIlverado for 45k miles, 2021 Equinox turbo for 80k miles and NEVER had a plug melt like the OP did.

Your vehicle operates on regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87.
Some fuel stations, particularly those in high altitude areas, offer fuels posted as regular unleaded gasoline with an octane rating below 87. The use of these fuels could result in engine damage that will not be covered by the vehicle Warranty.
For best overall vehicle and engine performance, premium fuel with an octane rating of 91 or higher is recommended. The performance gained by using premium fuel is most noticeable in hot weather as well as other conditions, for example when towing a trailer. See Towing a Trailer.
Do not be concerned if the engine sometimes knocks lightly. However, if the engine knocks heavily while using fuel with the recommended octane rating, contact an authorized dealer to prevent any engine damage.
We recommend Top Tier detergent gasolines, where available to help minimize engine deposits and maintain optimal vehicle and engine performance.
For additional information, visit https://www.toptiergas.com.

 

[mwelby]

Please check page 12 of the Top Tier gas brands. To Tier is an official designation not a Youtube video opinion. I don't use Sunoco because I don't have 1 near me but it IS indeed a top tier.
https://www.toptiergas.com/gasoline-brands/
Also note that NO WHERE in my manual for 2024, 2025 may be different, does it say to use 93 octane. Personally I don;t care if you choose to use rocket fuel but 93 is not required nor recommended by Ford. I run 87 in the Maverick as I did in the 2014 F150 for 165k miles, 2023 turbo SIlverado for 45k miles, 2021 Equinox turbo for 80k miles and NEVER had a plug melt like the OP did.

Your vehicle operates on regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87.
Some fuel stations, particularly those in high altitude areas, offer fuels posted as regular unleaded gasoline with an octane rating below 87. The use of these fuels could result in engine damage that will not be covered by the vehicle Warranty.
For best overall vehicle and engine performance, premium fuel with an octane rating of 91 or higher is recommended. The performance gained by using premium fuel is most noticeable in hot weather as well as other conditions, for example when towing a trailer. See Towing a Trailer.
Do not be concerned if the engine sometimes knocks lightly. However, if the engine knocks heavily while using fuel with the recommended octane rating, contact an authorized dealer to prevent any engine damage.
We recommend Top Tier detergent gasolines, where available to help minimize engine deposits and maintain optimal vehicle and engine performance.
For additional information, visit https://www.toptiergas.com.

My Ford owners manual for my 2025 says premium fuel recommended.

 

[john21161]

“Your vehicle operates on regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87…

For best overall vehicle and engine performance, premium fuel with an octane rating of 91 or higher is recommended. The performance gained by using premium fuel is most noticeable in hot weather as well as other conditions, for example when towing a trailer. “

This is the part of the owners manual I focused on. To my way of thinking, a forced-induction four cylinder engine, making over 100 bhp per liter has got to be pretty stressed. While Ford may have adequate knock protection programing to cover 87 octane, I don’t want to take the chance...especially now that my engine has suffered two melted plug electrodes.

Anyway, that’s what I think. Let’s see how things play out over the next few years.

 

[MavStangVa]

“Your vehicle operates on regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87…

For best overall vehicle and engine performance, premium fuel with an octane rating of 91 or higher is recommended. The performance gained by using premium fuel is most noticeable in hot weather as well as other conditions, for example when towing a trailer. “

This is the part of the owners manual I focused on. To my way of thinking, a forced-induction four cylinder engine, making over 100 bhp per liter has got to be pretty stressed. While Ford may have adequate knock protection programing to cover 87 octane, I don’t want to take the chance...especially now that my engine has suffered two melted plug electrodes.

Anyway, that’s what I think. Let’s see how things play out over the next few years.

If 87 causes plugs to melt the manual would not say " Your vehicle operates on regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87 ". That would open Ford up to lawsuits and warranty for life of the failed components. They test extensively before putting the "RECOMMENDATIONS" in the manual.
I want to know where you buy 91 octane? No where near me has it. 87, 89, 93 is available. Last fill up at Shell 87 was 3.69/gal, 89 was 4.89/gal, 93 was 5.29/gal. Also note the part of the manual that says "For best overall vehicle and engine performance, premium fuel with an octane rating of 91 or higher is recommended. The performance gained by using premium fuel is most noticeable in hot weather as well as other conditions, for example when towing a trailer. “"
If the temperature today hits 99 as forecast I should run out and get 91, but when it drops to 65 overnight should I drain the tank and get 87? Did Ford tell you the GAS caused the plugs to melt? If that was happening there would be many many threads about melted plugs. I don't tow a trailer but if I were going to I would fill up with 93. If I lose 25 HP on 87 I don't care because I am not racing my truck just running errands usually in 35 to 45 mph zones. If I had your experience I would be demanding the cause of it and what Ford will do about future issues if it returns. I also would have DEMANDED they replace all 4 plugs once they found 2 melted. I've run 87 since April 3, 2025 when I bought the truck and it has no codes. I have even a couple of times used non-top tier brands . I hope they actually corrected your problem but gas did not cause it and that is what I would be concerned about, what did.

 

[MavStangVa]

My Ford owners manual for my 2025 says premium fuel recommended.

I believe @john21161 quoted the 2025 manual and it is exactly like the 2024. There are qualifiers after the recommendation. I think you and everyone should buy the gas they feel is best but no where does Ford say it is required. It actually starts by saying the vehicle "operates" on 87. If they state that then I promise they have tested to see if it would lead to liability on Ford for ALL failures from using 87. Is there performance benefits to using 91? Absolutely, but not preventative engine failure benefits. Just my 2 nickels worth.

 

[mwelby]

I believe @john21161 quoted the 2025 manual and it is exactly like the 2024. There are qualifiers after the recommendation. I think you and everyone should buy the gas they feel is best but no where does Ford say it is required. It actually starts by saying the vehicle "operates" on 87. If they state that then I promise they have tested to see if it would lead to liability on Ford for ALL failures from using 87. Is there performance benefits to using 91? Absolutely, but not preventative engine failure benefits. Just my 2 nickels worth.

Sure, if you’re not concerned about possible preignition engine damage.

 

[john21161]

"Last fill up at Shell 87 was 3.69/gal, 89 was 4.89/gal, 93 was 5.29/gal."

That's a big difference in price between regular and premium! Here in Maryland, the price difference is less than a $1.00 a gallon. The last tank of Sunoco I bought was $4.63 a gal. I can see why you'd be hesitant to pay the difference. I'm glad your truck has performed reliably on 87.

As far as the cause of my melted plugs...whelp, that remains undetermined. The dealer service advisor was clueless. I doubt the technician knew much more. The service department did the minimum job required and no more. Honestly, that's what I expect now a days. They get paid (warranty) to fix broken stuff. They don't get paid to look for malfunctions that are not occurring while your truck is sitting in the service bay. Frustrating? Yes, but here we are. Frankly, I just needed my truck back. At the time, I had a wife with health issues, it was the middle of winter, and I had no time to fiddle around with Ford or the dealer. Was this the right thing to do? Maybe not, but its what I did. I accept that.

The reason I started this thread was my hope was that if other owners have the same issue, we could share information. Maybe I could learn something I didn't know or maybe somebody could share information that would benefit us all?

 

[MavStangVa]

Sure, if you’re not concerned about possible preignition engine damage.

I guarantee you Ford did not INTENTIONALLY put the 87 octane in the manual to get me to destroy my engine. I am not concerned because there is NO body of evidence that it happens. 100s of thousands of miles using it in various vehicles that ALL said it was designed to run on 87 and NO failures ever. READ THE MANUAL. Now tell me you DO NOT change the oil before the OLM recommendation says to. I'm concerned about possible tire failure but I don't avoid driving so it won;t happen. I'm concerned about possible cv failure but I'm not replacing them with Tremor cv's to prevent it. Show me any source that found 87 octane cause pre-ignition engine damage on Maverick ecoboosts.
https://www.jalopnik.com/1899452/ford-ecoboosts-dont-need-premium-fuel-reason-explained/
I am not suggesting you shouldn't buy whatever gas you want. But do not state damage that will not occur by following the Ford manual.

 

[MavStangVa]

"Last fill up at Shell 87 was 3.69/gal, 89 was 4.89/gal, 93 was 5.29/gal."

That's a big difference in price between regular and premium! Here in Maryland, the price difference is less than a $1.00 a gallon. The last tank of Sunoco I bought was $4.63 a gal. I can see why you'd be hesitant to pay the difference. I'm glad your truck has performed reliably on 87.

As far as the cause of my melted plugs...whelp, that remains undetermined. The dealer service advisor was clueless. I doubt the technician knew much more. The service department did the minimum job required and no more. Honestly, that's what I expect now a days. They get paid (warranty) to fix broken stuff. They don't get paid to look for malfunctions that are not occurring while your truck is sitting in the service bay. Frustrating? Yes, but here we are. Frankly, I just needed my truck back. At the time, I had a wife with health issues, it was the middle of winter, and I had no time to fiddle around with Ford or the dealer. Was this the right thing to do? Maybe not, but its what I did. I accept that.

The reason I started this thread was my hope was that if other owners have the same issue, we could share information. Maybe I could learn something I didn't know or maybe somebody could share information that would benefit us all?

I appreciate you starting the thread. And answers to the problem are needed. Maybe your truck the assembler bent the electrode installing them and caused it. Who knows. I spent 28 years doing filed service on machinery and we would replace the damaged parts and look quickly for causes but as you say warranty doesn't pay well if at all. But if the same models were seeing the same failures on multiple machines then investigation was done to find root cause. Wish you well with your wife's health and your Maverick.

 

[Optimus]

While I feel Top Tier fuel (or lack if it) has nothing to do with your EB issues, I will mention that labeling at the pumps is typically present with Top Tier grade. Photo below. I’ve seen various forms of the sticker, and sometimes in a different color scheme, but it’s normally right at each pump. I’ve seen it near the LCD screen, card swiper, and 87/89/91 buttons. With all the other labeling that goes on, it’s not always easy to spot.

 

[john21161]

I appreciate you starting the thread. And answers to the problem are needed. Maybe your truck the assembler bent the electrode installing them and caused it. Who knows. I spent 28 years doing filed service on machinery and we would replace the damaged parts and look quickly for causes but as you say warranty doesn't pay well if at all. But if the same models were seeing the same failures on multiple machines then investigation was done to find root cause. Wish you well with your wife's health and your Maverick.

I agree and thank you for your kind wishes.

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