Had a miss fire about a month ago and replaced the faulty coil pack. 2 weeks later had another missfire on a different cylinder...so i ordered the other 3 coil packs and installed them today. So basically why im posting is because-if you have a coil pack go bad, go ahead and order all 4 at once and save a little cash because the other coil packs are likely to die soon after the first one. After searching, I found many posts where they alltend to fail around the same time. I would have saved about $10 if i ordered all 4 at once (from ecstuning.com - who by the way has the best prices at least for the ATW engine coil packs.) So shes running real smooth now and especially so during cold startup...yAy~!