Is there a way to vent to unvent my homes drain system without opening up walls

They do make a ventless device for that and can go in walls, to vent.

Google Oatey and take a look at their AAV kit. You can add a vent to the lateral after the trap. http://ssmark.net/promotions/oateyaavannouncement.pdf Some AAVs are as cheap as $6 but the complete kits is about $26.

is there a way to vent to unvent my homes drain system without opening up walls
I assume that you have a older home with "S" traps. Why are you asking about vents at this point in time? Is there a drainage problem? What's changed after all these years? Let me know. Tom