Quick Question

What would happen if I were to go in and erase the whole program as well as the Data Memories and retype the code over again? Would or could this cause a problem. I have a copy of the program as well as the DM vaules.

The act of erasing the program and data memories should put the PLC back to its out-of-the-box condition. Be aware that some PLCs have the ability to read from non-volatile memory on power-up, so clearing RAM may not be all you have to do. You'll get more specific answers if you include the brand and model PLC you're talking about.

Its an omron sysmac c120 with a pro 15 programming console

Boy, you've got an old one......
Here is the procedure to completely initialize the C120 PLC to the out-of-the-box condition.
Be sure to do an I/O Table Register after you clear the PLC or you will get big time errors:

I've played with those plug-in programmers, they are scary.

I remember having to add a n/o bit for something I had wired to the controls. I broke out in a cold sweat.

Funny now I think, I bet most of us have had the cold sweats at some time or other, hehehe.