wideband setups + dsmlink + logging setup?

[Black95TSIawd]

Also make sure you have no exhaust leaks before the sensor or you will get a very false reading.

I've heard this statement before and it confuses me greatly. My car has a tial 40 on the o2housing which dumps out. Does that mean if you have an external gate, you cant use a wideband because it wont read right? I would think dumping out is a pretty big exhaust leak.