Emission light question

[hkka]

I fixed a rust decat pipe last week and the emission light was on after 2 days of driving because the garage put the 2nd sensor back on it (it was disconnect before)

Will the emission light go out if I unplug the 2nd sensor again?
Do I need to put something on the decat pipe hole to protect any dirt? I think there was nothing before.

Thanks!

 

[hkka]

The emission light is off after I fill up the fuel an hour ago.
maybe it will on later.
???

 

[Lagerlout]

The whole thing is a mystery.

GDi fitted my decat and I asked them about the lambda sensors - They said it doesn't matter about the second lambda and fitted it anyway.

2000 miles later and still no light for me!!