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

Next question is... do you have AAVs in you house? They look simliar to the pictures below... These may be the answer you are looking for... can install these without opening walls (usually).

If not, you will need to find out if they are allowed in your town/city (call plumbing inspector and ask him). Get back to me with answer. PS --->> You posted this question twice... remove one to reduce missing each other in cross posts. Thanks.