misfire on cylinder 4

[red6n2]

hi,

onvagcom i keep getting this error and occasionaly over the last few days my engine light would start flashing at me and and id struggle to get over 20-25mph, anyone know a reason as to why it would misfire ? it causes the car to shake like michael j fox and revs and power is restricted/missing

im changing my spark plugs either later tonight or tomorrow depending on if they were actually delivered at my house or not, coil pack is less than 12 months old, and HT leads from what io can tell are ok but may well be replaced in the not to distant future,

but has anyone got any suggestions ? i live up the top of a massive hill and it feels like my car will start rolling backwards when its restricted... wonder whose insurance claim that would be lol