01 ford focus - No.4 cylinder - In the dark

Need some advice on what to do please. husband changed spark plugs, hd leads and coil pack, after getting loss of power.He even changed to oil and filter. The car still judders but is slow to get up to speed at m.o.t they hooked it up to the diagnostic tester which came back with p0304 for the cylinder no.4 mis fireing. What would be the best thing to do next? Any advice accepted gratefully.


01 ford focus - No.4 cylinder - snm123


Did you ever get to the root cause of this problem? Reason I ask is that I have a misfire problem on cylinder 4, with the same fault code. Have replaced coil/leads/plugs.



01 ford focus - No.4 cylinder - Carl2

Only fit Ford plugs. The main dealers sell tubes of what I think is silicone grease . This needs to be wiped around the plug (on every part that sticks out of the head) . I assume Ford stipulate the use of this product to prevent such problems as you are experiencing. Not sure if this relevant to your car but the washer jets have been known to leak water on the plugs.


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