[john70t]

Get it scoped.
Absolutely. Now. A hundred bucks or two is nothing.
Get more than one opinion.

It probably doesn't matter what was "said". Or not.
The Title documents are the official legal conveyances of property with all known definitions and deficiencies.
There may be insurance to cover this (known) defect.

Current code may be for new construction only.
The existing y-pipe sewer configuration may be grandfathered.
Local conditions apply.

Personally, I would look to getting a separate street-hookup if a bunch of front yard mess is guaranteed though.
That may be expensive but would add value.