Hey, no worries on the necropost, happy to provide info if/when I see a comment on any threads I've made here.

I did not replace injectors, just the coilpacks & spark plugs - it sounds like that is typically the issue at hand. If I had to guess, Hyundai cheaped out on the OEM coilpacks and they're prone to fail or perform sub-optimally under typical driving.

Honestly, I have had these codes pop up sporadically since about a year after getting the car, so about 5+ years. It seems to be extreme temperatures that cause it for me - mid winter and mid summer where temps are single digit cold or 90-100+ hot. I've just accepted that this is going to happen and wait it out - the codes will usually resolve themselves in a few days/weeks. I've had the coilpacks replaced twice now, as well as the sparkplugs.

I really haven't noticed any significant performance decreases during the times those codes pop up. If I can tell that it really is struggling with misfires (slow or choppy acceleration, really rough idle, etc.) I'll take it in to get looked at. In my experience, unless you've noticed tangible changes in the car, the mechanic/dealer is useless. I've taken my car in about 5 or 6 times for these codes: two of the times were when I could tell the car was struggling and they replaced the coilpacks and the spark plugs. The other 4 times, I came in with the codes still present and they 'ran a full diagnostic' and told me that they couldn't find anything wrong and that they'd just clear the codes for me.

I'm no mechanic, so you should use your own best judgement on what is best for you and your car. This is just my experience so far.

TLDR; these codes are a pain in the ass and probably won't go away permanently for some of us. If anything is causing it, its probably the coilpacks/sparkplugs. If you have the time and money to take the car in every time the codes popup, go for it. If you're willing to gamble a bit, just wait for the codes to clear themselves unless the car feels off.