If you are suffering from the following conditions it could be your coils packs:
Missfire at idle
Ignition breakdown under load
When your cars misfiring, leave it idleing and remove and the replace the leads to each coil pack 1 by 1, until you find the one that makes no difference to your cars idle when its unplugged
take em out, grab a multimeter, they got – and + terminals on em, put your multimeter on 20 ohms (or the 1 with 20 on it duno if its ohms or like milli-ohms) and test. Good packs should have 1.6-1.9 i hear, mine ranged from 1.3-1.8. Suggestion is to test em while warm to. Also take off the boots at the bottom and look for plastic cracking or wrecked terminal
When your cars misfiring, leave it idleing and remove and the replace the leads to each coil pack 1 by 1, until you find the one that makes no difference to your cars idle when its unplugged
That will only work when the car is missing at idle. Coil packs generally fail under load to start with.