I have a 4" cast iron sewer drain going through my basement wall. I want to replace all the cast iron drain to PVC pipe. If I would to cut the cast pipe pipe going through the basement wall flush with the wall, is there a fitting I can insert into the basement wall to fit new PVC pipe. I was told by one plumber, is to actually go through the wall to replace it with new PVC pipe. On the outside of the basement I had all new PVC pipe replace with the exception of about 3" of cast iron that was used with a coupler to hook up with the new PVC pipe.