Boost and Air / fuel installation gauges
 

hello my name is Juan Pablo, I'm from Argentina, I want to install these 2 watches but I have some doubts.
My engine is Europe, where should I connect the air / fuel in the first or second lambda?
http://www.enfierrados.com/jp/minimotor.JPG

What is this sensor?

http://www.enfierrados.com/jp/sensormini.JPG

Sorry if this issue is not going in this location