I have had a similar issue with a Hyundai a while back, no codes but running on 3, my prefered method if possible is to remove one injector at a time and connect them back up outside of the engine using the car as a test bench, this way you can see if they are spraying, my Hyundai had a sized injector, electrically on a scope it looked fine,

https://youtu.be/Qa4g6NJHUfw