LS Harness Connection Coil Pack Subharnesses replace old, heat cycled wiring and loom. Commonly misplaced, damaged, or unservicable, your OEM unit could do with a replacement if you are having ignition issues. 
 
Also, great when paired with that brand new LS Harness Connection standalone harness that you're thinking about buying to provide clean, undamaged power distribution from your battery to your coils for faultless ignition firing at its best rate available.