Backed up Situation...need help...photo attached.

[phishfood]

Holy Crappp!!!

I can't believe I missed that! Once you mentioned it, I saw the pipe glued to the 1 1/2" connection of the AAV instead of the 2". The self inflicted beatings will not be pretty.

That is likely the cause of the backup right there.

[Matt30]

A 1.5" washer drain, vented, works just fine and has for many many years. Even a 1.5" drain, not vented stands a little bit of a chance. But when you have a tree like that, its just asking for trouble.

[Another-Plumber]

another photo added to my collection, lol

[Another-Plumber]

please remove that check vent fitting, im sure with the large amount of water dumping this wont allow enough air flow...