Has a p0306 & p0316. Idling rough and shaky at low RPMs. I installed a new spark plug and swapped coil packs with cyclinder 5. I still had the same codes come up. I did a compression test on cyclinder 6, I have 155 psi. So I swapped the injector today. Same codes and issues afterwards. I am at a lose here. If I unplug the injector harness or coil pack plug it prompts an error code for open circuits, so I don't think it's a harness issue.

Any help is appreciated. Thanks