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Misfire P0304 now P0303

KV331338
KV331338
in Ford Fiesta Club

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Hi All,

Complete newbie here so apologies in advance!

Recently bought a second hand fiesta as a runaround while trying to resolve many issues on my other car. The fiesta started misfiring so I changed all sparks, ignition leads and the pack. Temporarily cured the issue and it’s nowhere near as bad as it was but still had a misfire. Code read P0304 do cylinder #4. I moved the spark plug to #1 and injector to #2 to see if I could work out what the issue was. Now getting error P0303 - I didn’t move anything to here.

Spoke to a mechanic who did compression test and said that was fine so said it sounds like head gasket but he didn’t seem convinced. Tried a bottle of steel seal, nothing. 
Unsure of whether to get this guy to do the head gasket or get a second opinion. 
 

Anyone opinions?

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    What engine ?

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    • Author
    1 hour ago, unofix said:

    What engine ?

    1.4 petrol

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    Put the injector and spark plug you moved back into their original cylinder and see what happens. 

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    If the compression test was 'fine', then the headgasket isn't leaking around the cylinders.  I'm not sure why they'd want to replace it for this fault?

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    • Like 2
    16 hours ago, KV331338 said:

    I moved the spark plug to #1 and injector to #2 to see if I could work out what the issue was. Now getting error P0303 - I didn’t move anything to here.

    Be aware that the Cylinder number, Firing order, and Injector number (as identified by your code reader) are not all the same. There is also often confusion as to which end of the engine cylinder one is with these models.

  • Quote
    • Like 3

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