Man, that was quick.
71 miles into my 43% ethanol tank, the CEL went off.
I was Cline, starting to go over the bridge over the canal in East Chicago, by Mittal. The cruise was set at 65, and the turbo was spooling up. I'm not surprised that the CEL would come on in that situation.
The car was running well. No hesitation or missing that I could feel.
I got off Cline and hit the BP in Whiting on Indy as soon as I could. I added 3.146 gallons of Amoco Ultimate.
I'll go to Autozone this evening and use their scantool to see what the code is and to clear it.