On my '15 Explorer police. A few months ago I posted about replacing the plugs and 3 rear coils with new Motorcraft coils after getting misfire codes on two rear cylinders and finding the previous owner installed a set of noname coils all around. This time I don't have any codes yet the CEL was flashing. Why wouldn't there at least be a pending or history code stored? Is it because it only happened for 20-30 seconds? I assume the advice would be to now replace the front coils as well?
CEL flashing above 75 mph
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I checked both generic OBD2 and Ford. Nothing.
Autel 906BT
I believe the only time a CEL flashes is when the engine is making to much nox. I know it sounds to easy but I’d try some quality fuel injector cleaner. Could be as simple as a under preforming injector. Definitely any easy thing to try.
That is incorrect. A flashing CEL indicates a catalyst damaging misfire. The ECM has no idea how much NOX the engine is producing as there is no NOX sensor
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I would try a different scanner.
Does Forscan do that?
You can try it. Does that autel have access to mode 6 data?
Not really sure but it did monitor misfire counts on an older car, if that's what you mean.
Don't drive above 75, and /or try ForScan.
If you can check the misfire counters as you drive you can see which cylinder(s) are experiencing a misfire.
Once you've established which, then move on to why.
I.E. if it's ONE cylinder, then something unique to that one. If an entire bank, or all of them, it's something common to the set.
But start with your misfire counters to see the extent of the problem.
Once you've established which, then move on to why.
I.E. if it's ONE cylinder, then something unique to that one. If an entire bank, or all of them, it's something common to the set.
But start with your misfire counters to see the extent of the problem.
Do an exhaust back pressure test.
Sure but when I go to sell it, do I tell customers not to go over 75 too? That'll go over real good.
lower the price .
I was being sarcastic about the not going over 75 part. The ForScan part you should do.
Ordered 3 Motorcraft coils for the front cylinders before doing anything else. I can imagine the new ones in the back are causing an imbalance with the Chinese front ones and that's being interpreted as a misfire under higher engine speeds.
My owners manual said a flashing CEL indicates a problem that requires immediate attention compared to to a constantly lit CEL.
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