Can i go from a factory 17" wheel to a 16"?

Sure if you want to mess up the entire vehicle...

I know this is an old thread but here it is. No it will not mess up your vehicle that is wrong info, yes you can change rim size but you SHOULD not HAVE to change tire size smaller rim bigger tire/bigger rim smaller tire, reason for this is because your transmission is calibrated to a certain tire circumference if you do not do the above your speedometer will not read correctly

Now sense that's true will it hurt it to where I can drive it or just moh be off by five miles per hour or jus one or two miles per hour???