Hello all, I was driving today and when I pulled into a parking spot at my destination I noticed my check engine light came on after I put it in park. I have a 2002 Toyota 4runner sr5 with 215K miles. Automatic. The trac off and vsc off came on with the check engine light but apparently that's a safety feature toyota has, after that when letting it idle I noticed my idle was inconsistent, it would drop to about 600-700rpm and intermittently rev up to 1k before dropping down again. When stopped at a red light my idle was at 500rpm consistently. I took it to autozone soon after and got it scanned to find that it had the P0440 code. They said it was probably my fuel cap but I had already checked it and tightened it twice to no avail. Any help as to what it could be? I know it has to do with the evap system but there are many components.