Random misfire - This is kind of strange

[Nickel]

The other day I took the car up to Black Mountain in NC. I wasn't driving spiritedly, it was for a family matter. On the way back down the mountain my wife and I were having a little fun with a Maserati but I was still being pretty easy on the car. Noticed the CEL had come on. Went over all of my gauges, everything was perfect. Pulled off when I could just to inspect under the hood for a second. No weird signs, so I went to the nearest Autozone and got their code reader. Got a P0300 (Random misfire) and a P0304 (Cylinder 4 misfire).

So my friend came over with an OBD 2 tool and we checked the codes again and cleared them. We proceeded to pull both cylinder 1 and 4 spark plugs, they were identical and in perfectly good shape at 29K miles. Swapped 1 and 4's ignition coils, reassembled and started the car and let it idle for several minutes. No CEL came back up. I haven't had it on the road since then but I plan to test it this week. If a CEL does arise, theoretically I should get a P0301, at least that's what I'm hoping if it happens.

Could this be a fluke?

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[jrsimon27]

If it doesnt come back its s fluck if it does and throws the same codes you need to check the intake manifold the flaps inside them break up
How many miles in the car?

 

[Dominant1]

I had the same problem but only when i went wot. so i changed my plugs went wot again with the new plugs still 0300 code. So i went to my SCT x4 tuner and did a crank relearn ,the process was easy. now the problem is solved, no more misfires. Car is smoother feels more powerful and it idles so much smoother now.. try it you’ll like it..

 

[Nickel]

I had the same problem but only when i went wot. so i changed my plugs went wot again with the new plugs still 0300 code. So i went to my SCT x4 tuner and did a crank relearn ,the process was easy. now the problem is solved, no more misfires. Car is smoother feels more powerful and it idles so much smoother now.. try it you’ll like it..

It was a fluke for me. I've driven it hundreds of miles and no check engine light after swapping the plugs and coils and just overall tinkering with it. Theoretically it is possible during billions of combustion cycles, for there to at least be one small misfire. Could've been one small particle in the wrong place or anything really, but regardless, no issue presents itself.

 

[Mjv231]

Ive been having the same issue for the last 3 months... I noticed I been getting the same codes but this all started happening after I changed my intake to the corsa and the corsa exhaust. I did swap the ign coils and same errors... I read it may be my manifold I have a 2017 gt. If it is the manifold and I purchase the 2018 manifold should this issue be resolved?

 

[Losobaby]

i had the cyclinder 8 misfire and I took the car in on may 27th, here it is 12/4 i got my car back yesterday. ford blamed it on the sct tune and pcm....but i was able to get off scott free under warranty.

 

[whiteheadb]

2019 Same issue with the random mis fire on startup and then mis fire with cylinder 4 and 7. The car has a custom tune that I did not load, roush CAI and LTH w/custom CC, H pipe then out to exhaust tips. Could this be a back pressure issue or O2 sensor going bad. The car does not run ruff at idle or under normal load.

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