Pin 13 is not even used as an LED status indicator. You question and your code do not match.
What are you trying to do and what testing did you do to see if 13 and 2 do not light an LED the same?
Do you explicitly define both pins as output? I don't see this in the code supplied.
Not sure why this is a concern given that code, but if you are in doubt, you need to write specific code to answer your question. For example, define Pin 2 as output, then set it to HIGH attach an LED with resistor and see how bright it is. Then, define pin 13 as output, set it to HIGH and move the same resistor and LED over to check if it is the same.