2014 f150 5.0 93K miles

Have a history of issues with a #7 misfire on this thing. Back in April was in the shop for the same issue. They replaced plugs, but the misfire immediately came back. They let it cool and restarted and couldn't make the misfire come back. They had me drive it for two weeks and misfire did not return.

Fast forward to last week. First somewhat cool morning have a really rough idle when starting but after driving for a bit it smooths out. Does this every morning for the last week. Finally last night the check engine light came on. I have the following:

p0307
P0316
P0207
P0454

The P0454 is new and sounds like either wiring or a bad fuel tank pressure sensor. Can a bad sensor also cause a misfire? What's the procedure to replace this? I'm afraid it's raise the bed or drop the tank which is something I can't do in my garage.

Come on. Nobody?

the pressure sensor probably has nothing to do with the issue. the code for injector performance is perhaps a better place to start

I'd put a new coil on that cylinder and see what happens. Cheap and quick. Then, start looking at the fuel injector and fuel rail pressure.

Bonfire97 said:

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I'd put a new coil on that cylinder and see what happens. Cheap and quick. Then, start looking at the fuel injector and fuel rail pressure.

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Or just swap coils with a cylinder that isn't misfiring.

sts7049 said:

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the pressure sensor probably has nothing to do with the issue. the code for injector performance is perhaps a better place to start

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This.

The misfire codes are probably a symptom of the P0207 issue.

Quote:

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A P0207 code means that the PCM has stored a trouble code indicating poor performance on a fuel injector on Cylinder 7. This could be due to a bad injector, an open or short connection, an intermittent open or short, a bad ground or even a bad FCIM (though rare).

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I would start by looking at the electrical connections to Injector #7, especially if anyone has been doing work in this area and make sure the connector is tight and all wiring is in good shape.

After that then it starts to get a little heavy into diagnostics unless you just want to jump to replacing the fuel injector. If that doesn't fix it, then it is probably in the wiring or FCIM.

Another option would be to run some fuel injector cleaner thru it and see if you can get it to clear up that way.

Thanks everyone for giving me some things to check on.