Stopped to put gas in Durango,left engine running,noticed check engine light was on when I went to leave. Can removing gas cap with vehicle running cause check engine light to come on? How can the check engine light be erased? Thanks Z/

It will usually clear itself in a day or two if it was a loose gas cap that's been corrected.
If it doesn't clear, go to Autozone, borrow the OBDII scanner, and read the codes. Then erase to reset the Check Engine Light.