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!!
Don't rule out an injector. But a O2 'can' cause the ecu to dump fuel then pull it over and over . .
The pulling over to the side of the road imo to me sounds like wet plugs. Either way stop driving it. If it is dumping enough fuel during the misfire you could score the cylinder walls and require a new block.
I'd bite the bullet and take it in .. or if you must go DYI replace the upstream O2's and retest. but thats my internet advise.. see what others chime in with ...
I know they are expensive, but try replacing that O2 sensor. Def worth pulling it, just to see what it looks like.
Flashing CEL or on steady? That's surely a strange one. The fact that it resets when you key off and resrart tends to make me think pcm, but that's an expensive wild ass guess. I'd definately check things like pcm power and grounds and connectors associated with bank 1 injectors and coils.
It sounds like something, be it a circuit board or terminal is being effected by heat since it doesn't happen until youve been driving for a fairly long period of time.
Quote from: 6500rpm on August 13, 2020, 10:07:44 PM
Flashing CEL or on steady? That's surely a strange one. The fact that it resets when you key off and resrart tends to make me think pcm, but that's an expensive wild ass guess. I'd definately check things like pcm power and grounds and connectors associated with bank 1 injectors and coils.
It sounds like something, be it a circuit board or terminal is being effected by heat since it doesn't happen until youve been driving for a fairly long period of time.
The CEL will flash at first and then usually becomes steady after the beginning of the incident and we continue driving. Also, the CEL does not clear immediately after we restart the vehicle. It clears after multiple engine cycles. I believe the CEL is supposed to go off after there is a consecutive series of engine cycles (2 I think) where the problem is not detected. (Engine cycle meaning one start & stop of the engine).
You guys are awesome BTW. Really appreciate the feedback!!