My ses on my 2000 does not appear if its like 35-40f degrees or below. So basically its off all winter.

Come warm weather its back on with p1440.

Why does the temp affect this? I want to fix it but most solutions like evap canister or vent valve seem like they would not be temp dependent.

Once in a while the p0440 shows up too but right now its only the 1440.

All winter was zero codes. No issues. And last summer and fall it was on. Winter came and it went off.

Any thoughts?

 

Maybe because the evap canister expands in the warmer weather causing a leak.

 

https://maxima.org/forums/5th-genera...efuelling.html

 

That linked thread was actually my own question some time back....this issue I never solved.

Since then I learned its tempstature dependent.

Expansion and contraction is more than likely the issue. Have to pull the evap valve I guess and see if i can at least clean something.

Like was said above something must be expanding.