I don't think E10 or ethanol-free will make much of a difference in how your car runs, though your gas mileage will be slightly better without ethanol. If the gas is dirty, that might make a difference. Which reminds me, when did you last replace your gas filter? Your vapor-return system location might make a difference if you're filling up while your car is on an angle instead of flat. I had a D100 with the vapor canister disconnected and removed before I bought it. When I filled up and tried to top off with the front end pointing downhill, it leaked gas from that opening. If you top off on a severe enough angle toward the canister, gas might enter it. You might consider buying various sensors from a junkyard and seeing if they change anything. In my Dakota, a new IAC went bad less than a year after it was replaced, but the unit I bought from a junkyard has been performing fine going on two years.