We are remodeling a newly purchased home in Hawaii. Two days ago, I woke up sick from fumes. We just recently installed Central AC. The AC guy came out, but couldn't find a problem, but definitely smelled the toxin. I am staying in my friends house, who is gone for the week. He said that he may have forgotten to cap off the toilet pipe that leads into the attic. Should I tape it off? Is the AC pulling the toxins from sewage and spreading through the house? The bathroom fixtures are not yet installed. Help. Thanks