My house is approx 75 years old and has a trap (which are illegal to use now). I have been having sewer backup into the bathroom in the cellar and have had to have it snaked numerous times. The bathroom is not “vented” properly. Although the bathroom on the second floor is vented. I have been told that the trap needs to be removed as it is causing the backup. I have also been told that the yard needs to be dug up approx 10 feet from the front of the house because there must be something wrong underground. If the snake goes through the line o.k. it seems like the line would probably not be the problem. The trap being removed is going to be approx $2000. That would be worth it if it fixes the problem; if it doesn’t, I’m going to have to drink more than I should.