(See the best response by FishMan123.)

Problem description:
So the mapping icon size issue of making it 16 has caused a problem as expected. I have some icons that are bigger than 16x16 which are dense, but considering the movement of the character it causes a problem. If I am dead center of the icon which is 32x16 for example, there is no problem. But if I move 16 pixels left, or right of the object; I can now move freely through it, no more density. Is there a way to hard code this in? Or should I make an area tile that is 16x16 and add density to it.

Thank you in advance.
Did you change the bounds?
Best response
As the person above me stated, this is all due to bounding issues. You should look up the following in the DM reference:

Thank you, I will look through the DM guide and get cracking on it. Thanks again.