My brother lives a state away and has a 2013 Jeep Cherokee 3.6l

It had a miss and took to a shop it's coming up with P0302, P0520, P0522 codes.
Still missing after a plug change.

I am assuming the P0520 & P0522 might be related to the known oil cooler issues.

Does this engine have any known problems with lifters like the Hemi's or other unique issues that could cause the miss?
Could it be the oil cooler?

If I were closer I would do the usual compression, leakdown, injector, coil etc etc tests but I am not.

Hoping to give him good news from someone who has had more experience with those V6's.

Thanks.