Make Posts full width without sidebar

I am using the free Catch box theme and am attempting to change the layout for single posts. I would like for all single posts to look similar to the full width pagetemplate with no sidebar. Essentially I am trying to remove the sidebar from everything other than the home page. I have been successful in removing the sidebar from posts by deleting a line [Which this post editor won't let me show, but it is basically php get_sidebar] from single.php . I have also figured out how to remove other formatting such previous, next, post author, etc, although I haven't added it to my site yet. The problem I have is that I can't figure out how to make the post full width. Right now it only takes up a third of the screen, with a gray area where the sidebar used to be. How can I get rid of the gray area where the old sidebar was, and extend the post area to full width? My site is mcrtlife.com, and an example post showing the problem is Thanks.