Some of you may remember that I've been having a fairly regular CEL issue with my van since I bought it about two years ago. I still get random misfire codes even after having performed the fine-tooth comb A-Z. Rerouting the ignition wires according to the TSB and replacing the stock ones with Accel Ceramic wires has helped a great deal but I do still get some random misfires.

About two weeks ago I filled up my nearly empty tank with 87 at Valero. I noticed the pump did not say "Contains up to 10% Ethanol." I asked the attendant if Valero fuels in PA contain Ethanol and he just stared back at me. No help.

Anyway, after about 1/2 a tank my CEL went out. At next fill-up I went back to another Valero and filled up with 87 again. Same thing, no label on the pump and my CEL stayed off. I'm on my third tank of Valero fuel which I believe is Ethanol free and so far my CEL is still off. The van seems to be running really well and I don't think it's my imagination - idle is smoother and acceleration is better. I'm now in the process of measuring for any MPG improvement.

I'm wondering if my PCM hates Ethanol?

 

Wish I could get non ethanol fuel here. IMO all engines should not run that stuff.

 

Read on... http://www.bloomberg.com/news/2010-1...blend-gas.html

 

FWIW I chased a misfire code (although it was cylinder 4 every time) for about 3 months...ended finding out that it had a burnt exhaust vavle.
Replaced the heads - no misfire for almost a year now...