Tony Pacc wrote:
I want to install a new sink in the bathroom,I cant seem to remove a 1 1/2"
drain pipe that goes into the wall,I screwed the nut off but cant seem to
budge it,it's thin pipe and it pretty corroded,it seems like it should slide
out,I tried penetrating oil but it doesn't help .Thanks



Tread *very* carefully!

It's possible that's not a threaded pipe at all.
If it's "thin", it may be "tubular" drain type
which *could* be soldered to a bushing *inside* the wall.

See if a magnet sticks to it.

If it's brass tubular, get what is called a "Repair Trap".
It has a slip coupling that will slide over the existing tube.

My real point is: Don't "assume" anything!
You can turn a small job into a "tear-the-wall-open" project.

Jim