I would advise to change the plugs the same time you change the coil packs.
reason being when the coil pack shorts out it leaves a arc line down the enamel of the plug
if you fit a new coil pack to a plug with a arc line on it the new coil pack it will be faulty in no time as it will make it work harder due to the spark going everywhere on the plug.
reason being when the coil pack shorts out it leaves a arc line down the enamel of the plug
if you fit a new coil pack to a plug with a arc line on it the new coil pack it will be faulty in no time as it will make it work harder due to the spark going everywhere on the plug.