Hey guys! I'm new on here but I've been addicted to the EB engines since 2011 when I bought a new F150 with the 3.5L. I have had 5 vehicles with that engine because I love the power. I currently have a '19 F150 SCREW 3.5L 4x4 with lift and a 5 Star tune. Wife's car is a '16 Navigator 3.5L EB all stock with 86k miles. Her car is giving me the codes in the title. I have been researching the codes and possible causes for days and I'm struggling. P219A is air/fuel imbalance (bank 1) and then I have all the bank 1 cylinders showing misfire. The car will start to run really rough (loss of power, cutting out, misfires) after it has been running for 3-4 hours on a road trip. That's when the CEL comes on. We have experienced this 3 summers in a row when we take a road trip. If we pull over and shut the car off for a few minutes, the misfiring stops and usually the CEL will go away after a couple engine cycles. This year, the problem doesn't seem to be completely going away as the car is still acting up (occasionally) after returning from our road trip. The spark plugs were changed less than a year ago. I feel like it has to be something related to Bank 1 specifically like maybe the upstream O2 sensor. Don't see how it could be spark plugs, coils or injectors because the chances of all 3 on bank 1 failing at the same time would be unlikely and the problem only shows its face once per year. And help us appreciated!!