coil pack
#2
RE: coil pack
You normally don't need to change them until they break and aren't running as they should. The coil is on the top of the engine so it couldn't be any easier to get to. If it was burried in the engine and very hard to reach and I was changing something around it, then I'd probably change it if it would save me labor.
#3
RE: coil pack
one way to tell if the coil is on it's way out is if you are experiencing a miss with load on the engine. you may even get a backfire through the intake, but just make sure you don't have a bad timing belt or faulty valves. i just replaced my coil with a MSD unit and it functions perfect. i thought at first there was a timing issue, but these stock coils just are not made for 7000rpm playing. use good wires like Accel or MSD with low impedance for best performance.