If you haven't checked your plastic partition on pass side in engine bay, i wonder if it has been cracked and this causes injector 5and/or 6 to get corroded electrically. I am on my phone so I can't easily find the thread about it, but in my car I had to replace 5 and 6, both showing less than 200k to ground (ground faults) which occasionally caused stumbles until I could barely start it