Hi guys,
looking for some help.
I've got a misfire on number 4 cylinder with a fault code of P0304.
The fault code comes and goes but the misfire does not.
I have replaced the spark plug, swapped spark plugs around but the misfire remains, removing the HT lead on number for makes no difference when running and there is a spark.
I've looked around and all houses seem fine.
The fault code is confusing though as it comes and goes but the misfire doesn't and I think the fault code only relates to what the ecu can test so any thing electrical.
I can't think of any thing except a sticky valve but I always use 5 -30 oil.
How can I check this or could it be something else ( hoping it's not had gasket!)
Cheers,
Po79.

Try swapping the leads for cylinders 1 and 4 over at the coil, if the misfire moves then the problem is the coil , if not check compressions or better do a cylinder leakage test , check for air leaks , if everything is in order try swapping injectors over

As per last post

Thanks both!!!

It was the coil pack.

I'm a bit annoyed with myself as this was one of the first things i suspected but as I had a good bright blue spark and with No4 lead off the misfire remained the same I started to over think and forgot the basics and to triple check.
I think the fact the coil pairs cylinders together and the problem never shifted from No4 i doubted the coil.

I needed to unbolt the coil to get the swapped leads to reach (probably another reason i didn't triple check the coil) and once swapped the misfire immediately moved to number 1 cylinder.

But thanks once again,

Po79.

All sorted that’s the main thing