Misfire P0300

So here lately ive been getting a misfire code p0300. Plugs look good gaped at.026. Car has been running strong and still does but the code only pops up after a WOT pull, dosent happen all the time and cant see anything in the logs that makes me believe its even misfiring but still green in this tuning department, The only thing i haven't tried is moving the coils around to see if they are the problem.. The logs shows that its only #7 and #8 cylinders that are misfiring with both having counts between 7-12 on each cylinder. The tune has been in the car for some time now and has never had this issue before so im not sure its the tune giving me issues but also the weather has moved into the winter temps now which im assuming will have effects to the current tune. AFR is good and everything looks normal in the logs as usual. Just looking for options on what to look for or maybe something that im missing. Thanks

2015 Dodge Charger scat pack
Whipple #9 Stock engine

If you have around 100k miles and stock cam/lifters it could be the early stages of a failed tappet/worn camshaft.
Most of the ones I am aware of didn't have a noticeable miss early on but would set the code.
Oil analysis or looking at lift can be used to verify this.

Have you tried swapping the injectors to see if the misfiring cylinders change?

Broken ring lands generally show-up as a P0300 before soon becoming very obvious :(

Could possibly be the land rings if Whipple #9 means 9 psi boost on stock 392 internals. :shrug:

Didnt think about the injectors but i did have two on both banks with bad o rings could be that as well. I'm hoping its not the ring-lands but if it is 426 here we come!!

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Originally Posted by FstdodgeKY

I'm hoping its not the ring-lands but if it is 426 here we come!!

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I said the same thing if/when mine looses the lands. My stock RAM BGE is pushing 11.4 lbs boost. Maybe I'm not pushing it hard enough to do damage.

Attachment 94380Attachment 94381here is a log I did after making a few changes to the car. I did notice a few unusuall things. In a few spots the o2 sensors seem to be reading a different ends of the spectrum and also the misfires usually occour when I'm letting out of the throttle or when the car spins. Keep in mind the roads were wet when I made this log and hard to make any full pulls.

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Originally Posted by FstdodgeKY

Attachment 94380Attachment 94381here is a log I did after making a few changes to the car. I did notice a few unusuall things. In a few spots the o2 sensors seem to be reading a different ends of the spectrum and also the misfires usually occour when I'm letting out of the throttle or when the car spins. Keep in mind the roads were wet when I made this log and hard to make any full pulls.

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I'm not a pro tuner, so don't ask technical questions. It's little stuff I found messing with my tune. Sure are logging a lot of misfires. Looks like your leaning out (11.95) (I would think that's lean for a stock 6.4) the longer you stay in boost, starts out good though. Not sure what MAP 157 is in boost level, I have mine setup to show boost in log. Mines probable a little fat at 10.5ish, I'm running around 11.4lbs.
Mine was doing the same thing, I had to increase fuel mass by lowering number in open loop cells, odd, you would think raising them would, but i had to lower numbers to keep from leaning out. I'm logging (stft +ltft) for NN tuning the inj PW. It will show cells you are in during open loop. instructions (https://forum.hptuners.com/showthrea...-spark-advance)
You can also increase the MAP numbers in st/lt fuel graph to show more.

Hope others with more knowledge will chime in and correct if I'm wrong on things.

Thanks conan. I am logging sft+lft. And I hitting around 8 # of boost. I'll look at adding some fuel up top and see if it helps.

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Originally Posted by FstdodgeKY

Thanks conan. I am logging sft+lft. And I hitting around 8 # of boost. I'll look at adding some fuel up top and see if it helps.

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I see the LT and ST logs. Did you read this, https://forum.hptuners.com/showthrea...-spark-advance. Helps dial in the inj for fueling, you have pretty high neg numbers through mid range

borescope time.

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Originally Posted by Kmoney

borescope time.

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I'm thinking the same.

I'll have to get me one. any recommendations for borescope

Don't get the cheap Snap-on BK3000OR. I had to put a light in other sparkplug hole to boro mine.

I bought one of these which has a built in LED light ring and plugs into my phone. Images are good enough to determine condition of bore and piston.
https://www.amazon.com/Semi-Rigid-Inspection-Waterproof-Adjustable-Endoscope_8mm/dp/B07S1ZG7P3/ref=sr_1_1?keywords=WiFi+Endoscope%2C+3+in+1+Semi-Rigid+USB+Borescope+720P+HD+with+8mm+Inspection+Ca mera+IP67+Waterproof+with+8Pcs+Adjustable+LED+Ligh ts+for+Android+Smart+Phone+%26+iOS+iPhone%2811.5ft %29+%28Endoscope_8mm%29&qid=1573328734&s=industria l&sr=1-1

I did scope the clyinder and didnt find any evidence of bad ringlands and everything looked good and surprisingly clean as well. Guess I'll look at the tune and see what I can do there.

My car is a 2015 and I recently had #3 coil pack die on me. P0300 code and it finally popped a secondary circuit code for #3.

It would run fine at PT, but would stutter and miss badly at WOT. Started very abruptly after my switch to ethanol.

A new coil pack fixed it.

Hello, Did you find the solution? I'm having the same issue... Cylinder 8 is misfiring

I had a lifter half fail and would get misfires on my 2015 hellcat...They changed them and poof it was gone...46k miles