Trouble code P0304

[phatbak]

anyone know what would cause cylinder 4 misfire?

injector?
spark plug?

EDIT: sorry, '99 Expedition, 5.4, 82k miles

 

[phatbak]

changed all the plugs, and replaced coil #4 . all fixed

 

[smo0othride]

good deal, glad everything worked out

 

[pcrider]

Same problem with my o2 xp 4.6, dealer said the cylinder head gasket leaks and need replacement.

 

[Kevinw]

Still Studdering Away

I have replaced the wires and plugs and my 4.6 still has a PO304 code, I was wondering if it could be the injector.

 

[green03]

I would put money on an igintion coil if the exhaust smells funny. If it smells normal then it could be an injector stuck or plugged since condition 1 would be unburnt fuel and condition 2 would be lack of fuel.
Matt