Can I reroute my kitchen sink drain pipe to go sraight down to the stack in the basement? Unattaching the cast iron pipe.

Hi Jammim.

Unfortunately, that probably won't work too well if the cast iron pipe goes into the wall. Here, that cast iron pipe isn't only a drain pipe, but it also acts as the vent for your kitchen sink so eliminating the cast iron will probably create a problem in draining/venting the sink.

There may be an alternative here IF your state/town/city allow mechanical vents (also called AAVs). Check to see if your state allows AAV (air admittance valves), and if they do, pop back and we'll discuss more if you want, OK?

Mark