how do i know if mine needs to be tightened? is it common that it comes loose? and if so can i just climb underneath and tighten it myself or is it hard to get to? thanks for the help.

What symptoms are you having that would cause you to thing that the front sway bar is loose? I have never heard of a sway bar coming loose, unless someone installs one incorrectly and doesn't torque the bolts right. You would need to jack up the front end to get easy access to the sway bar.

i guess just call it paranoia ir ead one of nonstopreds post about how he needed to have his titghtened so it hought maybe i should check.

You can always check the bolts during your next oil change, but unless your handling is significantly different from what it was when you bought your 'stang I wouldn't worry about it.