What are these markings ? (2017 ram)

Bobzilla said

I just noticed this thread. If anyone else runs into a misfire issue like this on a 3G Hemi with this style coil, a good test is to swap the coil from the offending cylinder with one from a cylinder NOT setting a code.
If the code sets on the same cylinder as before the coils can be ruled out.
If the code moves to the new cylinder the coil is the cause.
Same tests can be done with the spark plugs themselves.
The coils do not usually fail in a full set of 8 at the same time.

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I thought about going that route, but i didnt want to invest the time in chasing it down like that

The truck is at 96K miles and the service interval for plugs is 100K, so they all had to be done anyway

The coils, i could not find a service interval for but I figured, they all have the same miles under the same conditions...kind of like bulbs, if one of them burns out, the other one usually isn't far behind

Plus, I liked the opportunity to go with some hotter coils to hopefully get a little bit better fuel mileage out of the truck