Never Seen THIS Cause a MISFIRE - Part 1 (Jeep V6)

2016 Jeep Grand Cherokee came in with a low power complaint. Test drive revealed a pretty consistent "fishbite" MISFIRE. Owner already replaced the spark plugs and ignition coils...of course ;D Will this be another case of JUNK aftermarket parts? Or is there another variable? THINKTOOL PROS: https://www.amazon.com/dp/B08XXWHQVJ?tag=onamzpineholl-20&linkCode=ssc&creativeASIN=B08XXWHQVJ&asc_item-id=amzn1.ideas.NHZL00NIDEPF Enjoy! Ivan