My mother recently puchased a 3 year old home. After she moved in we noticed that her hall coat closet always had a foul smell. I found the odor was coming from what looked like a common air vent in the closet. When I removed the vent grill, I found a pvc pipe, which is the is the toilet vent. It doesn't go up & exit anywhere, it ends right there in the closet. Is there any building code that states this is not right?
Thanks-

This is not only a code violation but it's also a direct open connection between your mothers home and the city sewer allowing sewer gas to enter her home. Sewer gas is harmful to your mothers health and the methane content is explosive. My suggestion for a TEMPORARY repair would be to install a AAV,(air admittance vent),(see image) on the open pipe at once or, at the very least, cap the open pipe. Then call in a plumber to either run it out the roof or revent back into a existing roof vent. DO NOT LET THIS SLIDE!! GET IT REPAIRED AT ONCE. Good luck, Tom