Intermittent cylinder 4 misfire

[Fistlaw]

What to do next?
Replaced plugs, coils and upgraded the injectors. The light goes on, I clear it with a JScan…a week and ~200miles later it’s back.
Runs super smooth but I’m perplexed what next?
Pix for attention…

 

[Fistlaw]

What to do next?
Replaced plugs, coils and upgraded the injectors. The light goes on, I clear it with a JScan…a week and ~200miles later it’s back.
Runs super smooth but I’m perplexed what next?
Pix for attention…
View attachment 128712

View attachment 128713

Here’s another of all the codes:

 

[BLACKJKU]

Did you try a ECM reset?

Did you use OEM parts that you replaced?

 

[Fistlaw]

Did you try a ECM reset?

Did you use OEM parts that you replaced?

Yes, OEM
I’m not familiar with the ECM reset process.

 

[BLACKJKU]

Yes, OEM
I’m not familiar with the ECM reset process.

How to Reset the ECU on a Jeep Wrangler JK

While there are folks that swear resetting your ECU does absolutely nothing, it's a common practice among automotive enthusiasts. The ECU (Electronic Control Module) "learns" your driving style and the parts in your ride by storing information in its memory, information that it gathers using a...

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[WestCoastDan]

I recommend examining the wire harness at/around cylinder #4.
If you feel ambitious, consider swapping the plug and coil pack from #4 w/ another and see if the misfire remains on #4.

I would also consider doing a compression/leakdown test.
Although rare, I recently read a post stating that their misfire was the result of a crack in the head.

 

[Fistlaw]

Great advice. Thank you