K series ignition coils.
 

Should K series ignition coils be routinely changed at set service intervals.
Or only if/when they are found to be causing a problem?


Likewise with the HT leads?

The one time I changed a set of coil packs, one of the new ones failed two weeks later and I had to put the original back on!

I wouldn't bother unless they are showing a fault, T4 will give you a reading of the coils should you need it.