About 2 years ago I started randomly getting a multiple cylinder missfire. I went online and bout 6 new hanshin ignition coils for my 99 maxima. I installed them with some new plugs and everything was great for about 3 months. 2 rear ones blew again so i got 2 more (under warranty) and i was all good until this past Wed. It was the first really hot day of the year in ct (like 95) and my car started missfiring really bad on my way home from work. I pulled the codes and it was a cylinder #4 missifre. Assuming it was a coil pack again i called up the place i bought them from and they are shipping me another.. within 7-10 business days. I puled out the one that was in there to see if it was dammaged and first I pulled the top part off from the shaft and then just the shaft ripped off and now the connector which goes around the spark plug is stuck inside the engine.

I noticed that the parts inside the ignition coil were very corodid.

Any clue why this is happening?

The codes im getting are P0304 and P1320 and an o2 code.

 

Cylinder 4 misfire, a random misfire code and an 02 code

As for why they are continuously failing...IDK. 1999 cars are notorious for faulty coil packs..maybe the packs you bought online were used.

As for the boot that came off of the coil...try using some long needle nose pliers to grab the boot and pull it out

 

Im assuming its my coil pack because even after removing it (what i could get out so far) nothing changed.

The ones i bought looked brand new and were advertised as new so ive got no reason to think they were used.

I just thought it was strange that it was so destroyed inside after a year and half.

 

With everything made in China now a days, get used to replacing everything in a year or less.

 

Any oil into the spark plug tubes? If the boots were deteriorated enough to tear, they may be leaking spark and causing the misfire rather than the coils themselves.

 

One thing I can promise you, if they aren't OEM hanshin from Nissan the odds of the coils either not working right or failing is extremely high. I know its expensive but spring for them, it will be well worth it. Your corrosion could be caused by the incorrect electrical resistance from your aftermarket coils. They tend to heat up a lot faster toward the top near the connector. Also, not sure what plugs your using but if you are using a cheap plug with a low heat rating, it could also be the cause for your problems.