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2000 Honda Accord with Summer sporadic Check Engine light

I’ve got a 2000 Honda Accord LX,with about 197K miles on it, and the last two summers it has had a sporadic check engine light, but only during the summer. It typically starts up about May, and stops about mid-September. When I’ve gotten codes, it has typically been P0172 and sometimes P0170. Temperature doesn’t seem to have anything to do with it (this past August was pretty cool (for August) and I still got the sporadic Check engine light). Most often (but not always) the light comes on either shortly after fill-up, or when the gas tank gets down to about 1/4 tank. The light comes on, and lasts about one cycle (50-100 miles, depending on what kind of driving I’m doing).

My own theory on why this happens only in the summer is that I live in Metro Atlanta, and I understand they slightly change the formulation of gas for the summer in this area. I don’t know what the change is, but I assume the summer formulation puts something just on the edge of detection, and every once in a while it will go over the edge to trigger the Check Engine light. It doesn’t last long, as one cycle later, it’s not there, and the light goes back off. I’ve been short of money the last couple of summers, so, knowing the sporadic nature of it, I haven’t tried to get it fixed. Assuming I have the money get this worked on next May, anyone care to speculate on what is causing this, given the P codes and the apparent sensitivity to summer gas formulations?