So my engine light came on last week in my '02 wrangler and I had the code run, it said it was a cylinder 1 misfire. After getting the diagnostic done on the engine, the mechanic said it could have been the spark plugs (turns out had been a while since I had them replaced) or the ignition coil pack. The jeep has 130k miles on it and when I bought it at 112k, I'm not sure if the previous owner had replaced the coil or not. Anyway, I replaced the spark plugs and the engine light went off only until the next day. When it came back on I ran to autozone and picked up a Duralast ignition coil that autozone said would work for my 02 6cylinder. Again, the engine light turned off but this time came back on after about 400 miles. When I went back to pepboys where I initially got the code run they said that it could have come back on because the aftermarket coil isn't actually compatible with my jeep. If that is the case, wouldn't the check engine light have come on earlier? How likely is it that the coil is not compatible, would I need to get the OEM? Any other ideas of what it could be? Thanks in advance, any suggestions are much appreciated.