I just put my second tank of gas in, and the Check engine light came on. I went to autozone to read the code and it was the cap as I thought it was. I have taken it off and put it back on a number of times. I even had the code cleared, but it came back on. We have a little Ice and cold temps in St. Louis right now, so I don't know if that could be part of the issue with not sealing well... Any Ideas?