NB1 Sporadic dead miss on startup.

As stated, dead miss occurred cold or hot. Sitting and holding engine RPM above 2500, exhaust smell would indicate rich mixture and CEL would illuminate. It would fire on all 4 after a short time. First thought was leaking down injector. I pulled the plugs for inspection 1&2 looked normal, 3&4 center electrodes had shiny black almost baked appearance with open cracks. I have never seen electrodes with that appearance. Replaced all plugs and still had the same occasional dead miss which was lasting longer. Purchased coil pack from Mazda and started removal procedure. The coil pack plug lead order is marked on the pack frame (4 1 2 3). I noticed 1 and 4 were reversed. After removing the coil pack from car and inspecting it, I discovered complete corrosion in the bottom of number 4 coil tower. I assume that caused the dead miss. Engine started and ran great on roadtest.

Finally the question: Any possible damage from reversed plug leads? The car ran fine for the 10,000 miles that I have owned it.  Did this cause the corrosion in coil? 

Thanks

The coil corroded because it was exposed to atmosphere 

No damage at all from reversed wiring.  The coil is double ended so the spark goes down one wire, across the plug gap, through the cylinder head, across the other plug gap, and up the other wire. 

There are only two times it matters.  One is on waste spark Fords with the original plugs.  Only one side of a plug really wears, so Ford saved money by putting platinum on the ground OR center electrode and making the plugs position specific.  The other time is on Saturn 1.9s because they used circuitry in the coil pack to determine if 1 or 4 was the one firing, and this was used instead of a cam position sensor.  (It even worked most of the time)

My damage to NB with a bad coil was destroying my cat. Many years ago and was still under warranty. 

In reply to GTwannaB :

The CEL started flashing only twice when I attempted to limp home. I stopped and reduced throttle until it stopped flashing.

In reply to Pete. (l33t FS) :

Thanks