Text Only Goes 1/2 Way Across Screen

I am using the Small Business SEO 1.0.3 theme for my web site https://www.dahlbergmotors.com. To make this web site look more like a web site as opposed to a blog, I went in several of the .php files and removed the getSidebar() syntax so it wouldn’t appear. However, now when I put information into the body of the page, it only goes about 1/2 way across the screen and stops where the Sidebar previously was. I know I need to extend this page to go where the Sidebar used to, but am unaware how to do this. For an example of my problem, please go to https://www.dahlbergmotors.com and click on the Vehicle Inventory tab. You’ll see how the text doesn’t go all the way to the right.

What do I need to modify to get this to occur? If I should upload any of my .php files for review, please let me know.

Thanks in advance for any assistance provided!

Chad