Things that make ya go Hmmm

I've been doing battle with the dreaded CEL& code P1443. I've replaced 90% of the fuel evaporative system with no sucess. I find now that when the outside temp drops to below 36 degrees F the CEL goes out. I can reset the puter and stay good until the temp goes up past 36 then I get the CEL again and the code. What componant is the temp affecting..........Hmmmmm................