Oh and get this, by chance I ran across someone with a honda civic who gased up with premium at Chevron in Livingston very recently. Had the same problems.
On another note.... I fixed my problem. It seems to be part bad fuel but was actually a minor role in my problem. I'm fixing that by putting in fuel drier and running it down dangerously empty past the light. Then filling up and adding a bottle of techron.
Anyhow, I pulled my plugs tonight to replace them. Remember how I mentioned the one coil that had a sooty dark residue? Well the threads on the plug came out dark black, ground electrode tan, center electrode tan and base of the threads (inside combustion chamber) tan.
The other 5 came out identical to each other but different from the one odd duck. They came out rusty color threads, tan ground electrode, tan center electrode and base of threads black. In other words they looked good. In fact they all seem to looked good. Just that one odd duck out of the bunch was not right.
Here is where it all fell together. The one odd ball sparkplug, well when I dropped in the socket to remove it, I used my fingers to set the socket and extension in place and turn it to set. Well it seems that it was so loose, it was coming out with just my hands. ONE LOOSE SPARKPLUG. The black residue on the coil turned out to be carbon deposits from exhaust gases escaping. The black threads on the spark plug, also the same thing, carbon. The plug was in enough to stay put, but loose enough to allow exhaust gases to escape.
Wow........ Once again, that is just crazy. I dodged the bullet by spending $3 on a bottle of fuel line drier, $7 bottle of Techron, $1 plug gap gauge, $2 dielectric grease and antiseize, and 6 oem iridium plugs I had sitting in my trunk waiting for a long time. She's back again out on the road. My motor is quieter now. What I once thought was noisy valves turned out to be a loose plug. It actually has more power now, revs MUCH smoother and accelerates CONSIDERABLY faster. The car is also quieter inside.
I say my problem was 90% loose sparkplug,10% bad fuel.