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Att tech's misfire issue bank to bank

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#1
hey im new to this platform!

So my issue is that when WOT only in sport mode the explorer throws misfire codes . The other issue is that it only happens at higher rpms as load goes up . I did have a tune an bov but have been removed for testing purposes. It sets one whole bank 1-3 an then if it resets it self an i do another wot hit it would then throw opposite bank 4-6. The explorer hits hard down low but as soon as it sees more load i loose all power so i lift . It dose trigger the codes faster with tune in it but with factory tune it takes abit longer to set light.

Ive looked at pedal position to verify not loosing singal an its good till i lift .
Also both banks respond perfectly right down to correct lamda
Ive also checked cams an they are working adding an subtracting as they should
oil pressure rises with rpm as it shoud.

I dont know if theres any ford techs in here that know correct readings of the map an wastegates for factory.

The suv besides that is perfect just when your trying to get busy it shuts you down lol



Any help or insight would be greatly appreciated

Ramon
 

TMac

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#2
Misfire codes are generally going to be injector or spark related. You'd have to give a lot more info- mileage? fuel? tune? mods? Since it switches banks, it could also be the crank or cam sensors. O2 sensors are also a possibility, but once again, that bank switching problem makes it more difficult to diagnose. Can't really imagine any wastegate issues.
 

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OP
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Thread Starter #3
2020 27k i use 93 fuel always with factory tune, also everything is back to stock form to find issue. But with tune "sct canned" an turbosmart bov an drop in filter it just triggers misfires faster.So my guess is its air/fuel related or somthing is loosing communication . It feels like its protecting it self from melting lol

Both catalytic convertors were changed to the updated version ones

Dose have factory plugs the first time it showed drivers bank i pulled the plugs an they look perfect no signs of crack or corrosion havent checked drivers side.
 

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Thread Starter #4
So this is the data log the one to 6100rpm an other one is still to the floor as you see the pedal is still at 100% but dropping rpm so I lifted.
 

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TMac

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#5
The fact that a misfire causes the ECU to "lift" is completely normal.

Where are the lambda values that you say are "correct"?

Honestly, it's a tough thing to diagnose. I'd start with the injectors. If it were me, I'd first try running a bottle of techron through it to see if it makes any difference. Add a bottle to a tank of gas as instructed driving normally (don't launch with it), for a couple hundred miles, then on the subsequent tank of gas (tier 1 gasoline) see if anything has changed. After that, it's plugs and/or coils.
 

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#6
Do you have the Freeze Frame from the codes? If it's going lean under load check all the hose clamps on the boost side of the intake tracks, maybe there's a leak somewhere.
 

TMac

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Do you have the Freeze Frame from the codes? If it's going lean under load check all the hose clamps on the boost side of the intake tracks, maybe there's a leak somewhere.
That's probably a good idea, but I don't think that a small boost leak prior to the throttle body would cause those types of bank-to-bank misfires.
 

l1tech

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#8
Given that you are getting misfires on both banks the very 1st thing I would do is a misfire profile relearn to rule out false information that may be triggering the codes. In order to do it you are going to need a capable scan tool. It can be done with FDRS obviously as it is the OE scan tool but I am not sure about any others. Can you actually feel it misfiring or does it just go into limp mode?
 

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Thread Starter #9
Update guys so I replaced All the plugs an tried it again weird thing it set p300 an all cylinders misfire
 

FORZDA3

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#10
Well, there are two things that can affect all cylinders at random intervals. 1) fuel flow/pressure/contamination and/or 2) spark error from crank sensor or timing ring.
 

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Thread Starter #11
ForzDA3 sent you a pm
 

l1tech

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#12
Have you performed the misfire profile relearn yet?
 

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Thread Starter #13
Yes and just tried it again now a same thing. But it keeps showing 30psi

Heres afew pics of freeze frame an log
 

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Thread Starter #14
Tomorrow gonna put pressure on map a see if I’m seeing the same boost pressure as ecu.
 

l1tech

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#15
What does the map read with the key on and engine off? Will it misfire if you put it in tow/haul mode?
 

FORZDA3

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#16
Tomorrow gonna put pressure on map a see if I’m seeing the same boost pressure as ecu.
I didn’t see your pm until now. I’ve looked at the data posted and nothing really jumps out. The manifold absolute pressure is local baro plus boost, so you’re at about 15psi boost which is close to normal for stock tune. I’m thinking ignition timing, including any knock retard should be looked at as well.
 

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Tomorrow gonna put pressure on map a see if I’m seeing the same boost pressure as ecu.
You seem to be convinced that it's boost related. Why is that? I can't see that as the issue since the same amount of boost is being produced at lower load levels and yet you're not seeing the problem occur there according to you.

You also had a tune on it, and then removed the tune. What tune? Did it blow out a head gasket? Any leaks you can see? I would be more inclined to look at sensor issues at this point (crank, cam, 02). I suggested you try running injector cleaner through it for a tankful, and yet it doesn't seem you did that. If you're wanting help, but not willing to follow up, what can anyone do to help?

I'm wondering why you're trying to do this by yourself- are you out of warranty? I ask these questions since it seems you're looking for an easy fix for a very difficult problem, and yet from your posts, it doesn't seem like you are knowledgeable enough to fix this on your own.
 

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#18
Generally speaking, for purposes of misfire, the crank sensor is used to sense out-of-range angular momentum changes. This allows the ECU to detect individual cylinder misfires (depending on the granularity of the crank position sensor). From what the OP has written, the ECU is not narrowing it down- this means that there are multiple misfires being detected on both banks. The only sensors that deal with separate banks are the EGT and O2 sensors. This would trigger me to look at the fuel system first, unless it's a bad crank sensor.

Since the problem seemed to switch banks, and after replacing plugs it's basically reporting general misfires on both banks at high RPM and load, it could also be dirty injectors, the HPFP, the crank sensor, or possibly another mechanical issue.

@l1tech recommended a "misfire profile relearn". Not being a Ford Tech, I don't know how this is accomplished, and neither do you. None of these can be dealt with by the average back-yard mechanic.
 

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Thread Starter #19
You seem to be convinced that it's boost related. Why is that? I can't see that as the issue since the same amount of boost is being produced at lower load levels and yet you're not seeing the problem occur there according to you.

You also had a tune on it, and then removed the tune. What tune? Did it blow out a head gasket? Any leaks you can see? I would be more inclined to look at sensor issues at this point (crank, cam, 02). I suggested you try running injector cleaner through it for a tankful, and yet it doesn't seem you did that. If you're wanting help, but not willing to follow up, what can anyone do to help?

I'm wondering why you're trying to do this by yourself- are you out of warranty? I ask these questions since it seems you're looking for an easy fix for a very difficult problem, and yet from your posts, it doesn't seem like you are knowledgeable enough to fix this on your own.
okea so first things first I’m no punk an I’m looking for insight from others ! I also am a mechanic this platform is new to me the explorer did have shortblock replaced by ford. But ford is out 2 months before they can look at it. So I decided to see if maybe someone else had similar issues. As for mods like I said it had a canned sct tune an drop in filter with turbo smart upgrade. I’ve swapped back to stock parts an tune an same issue with codes only differences is with tune it triggers light an misfire faster to set.
I’ve also already ran 3 tanks since issue since you know everything about me an I cant follow up if I’m doing testing like driving to run afew tanks threw it.

Also I do Have software to do profile update ford IDS
 

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Thread Starter #20
What does the map read with the key on and engine off? Will it misfire if you put it in tow/haul mode?
Haven’t tried tow haul mode an it’s showing .5-.8 idle for volts
 



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