Question on Spark Plugs and Cable Replacement

Hi. A lady reader here. Thanks for the great instructions. I like to do the work on my car if it's something simple ie. brake pads, oil change, spark plugs.... I'll just say that the only major problem I had was finding the 14mm, 12point spark plug socket without ordering it. Oh boy! Not a good experience at all. Finally found one from a place I never even knew existed, with the help of a customer at a local auto parts store. You talked about the special socket needed, but they are not readily available at your local stores. Unfortunately, my problem was not solved. Still have misfire codes, 300, 301, 302, 304. Recently I drove through a large puddle of water which I didn't realize had so much water. It hit under my 2011 mini cooper with a lot of force. I was stunned because my 12v charger sparked as I went through the water. Later I realized a penny had falled in there. Anyhow, my poor mini remains sick sputtering, flashing to not flashing yellow check engine light upon first starting out, decreased power, low idle in neutral, rough ride throughout entire ride. My ex-warranty expired about 30 miles ago. So trying to do as much research as I can, as to not be taken advantage of if I'm not able to fix it myself and have to take it in to be repaired. Any opinions, advice, suggestions, or comments? A little history: had work done in Oct, a misfire on #3 was dianosed at that time, ignition coil was replaced.



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[Nick at Pelican Parts]

To isolate the misfire, I would check spark, fuel and compression on all cylinders.

- Nick

[htexans]

I'm trying to look up how to check the spark. I've found information on how to do a compression test. Will that test all of what you're recommending? I also plan on replacing all the ignition coils, and possibly replacing the spark plugs again even though I just did that 2 weeks ago. Would that be the best idea?