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Diagnostics code PO304

Gingerbreadlady
Gingerbreadlady
in Ford Fiesta Club

Featured Replies

Hi

My 55 plate fiesta started playing up and the engine management. So i had someone do a diagnostic test and code PO304 came up. 

Does anyone have any ideas what it could be. Thank you in advance. 

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    am getting Cylinder 4 Misfire Detected

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    • Author

    We have changed the injector, plugs and coil pack and it's still misfiring and that code keeps coming up

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    You might have no or little compression in that cylinder. A compression test would need to be done to check for this.

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    • Like 1

    Have you changed the ht lead on cylinder 4. It is the one on the right standing and looking at the front of the engine.

    If your spark plug gap is 1.3mm you could reduce it to 1.0mm, this will put less stress on the coil pack and it might run better.

    Does it run ok sometimes?

  • Quote
    • Like 1

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