Hi, I have a mk1 04 1.4 petrol focus with 64k miles on the clock,
While travelling today my Yellow engine light came on and I notice the
car was struggling to get up hills (holding back)
Once home read the code which was p0304 cylinder 4 misfire. I have checked
plugs and HT lead which are all okay so looking like coil pack failure.
My question is there any way to test it to make sure before I fork out on a new one,
Is there any one out there who has had the same problem and are these coil pack prone
to fail around this milage. any help appreciated need car quick for work ,many thanks

The voltage can be tested from the coil pack with a multimeter, or test with a known good one.

Just letting you know problem fixed, I got a coil pack from the scrap yard £15.
The car now running sweet as a pea. The old coil pack had no tracking marks from
no. 4 outlet or underneath it so must have gone wrong inside somewhere.
Once again thanks for your reply.

Glad you got it sorted .