re: New speed queen overflows 1.5" drain

On a new house. Didn't always be that way. House is 50 years old. When they come out with new codes you don't have to go update everything. I did get it fixed. Cut the horizontal 1.5 pipe with a reciprocal saw and it was pretty clean past that point from my snake etc. used a proflex clamp and transitioned to 2" PVC trap and drain. Seems to be fine now.

The drain where it connects to the tee behind the sink seems to be 2". That tee has a 1.5" off to the left for the washer. It runs through a stud also. Would be a much bigger job to remove that tee and replace the pipe through the wall. Just need to test heavy duty cycles which pump more water out during the rinse and spin phase.