How do I fix this vent cast iron pipe?

[tmcdouga81]

It's under the left of the sink. The smell in the house is pretty nasty.

I was thinking two fernco couplings and PVC, I am not sure how to get it on the base part.

Any ideas?

Here's a link to the image...

http://picpaste.com/pics/16835733_1809409155988266_913401832599797998_o-Uq9yINyy.1487713569.jpg

 

[Reach4]

Image works now, after clicking on your link.