Kitchen sink DWV vent overflows. Puzzled

[Daybyday2k]

The picture shows what i assume to be the dwv vent. It is a tall pipe going upward ending just below sink basin and open ended, lately when sink drains, this pipe overflows and floods base cabinet. How to fix? I dont understand why this sink is the only one with the seperate pipe like this and with an open end??? Does this piece tie into the sink drain behind wall??
Do i get on roof and look for this vent and run garden hose down? Thanks for feedback.

 

[PETE 123]

part blocked waste pipe.

 

[oz-plumber]

It has a trap on it so I doubt it would be a vent.

Just cap it - even cover the opening with tape, and see if it effects any of your drainage.

If it wasn't trapped, you would have sewer smells throughout your cupboard and the room it's located in

 

[snowhead]

As there is what appears to be a Water conditioner on the left , I'd say the tall waste pipe was for the drain from a previously fitted Water softener.
The waste will be partly blocked behind the base cabinet if that pipe hasn't been overflowing before.

What is the corrugated pipe in the bottom of the unit at the back, is it connected to anything or is it electrical?

 

[Daybyday2k]

As there is what appears to be a Water conditioner on the left , I'd say the tall waste pipe was for the drain from a previously fitted Water softener.
The waste will be partly blocked behind the base cabinet if that pipe hasn't been overflowing before.

What is the corrugated pipe in the bottom of the unit at the back, is it connected to anything or is it electrical?

Dishwasher discharge goes to disposal.