Just fitted a decat down pipe yesterday, but could not get both sensors out of the old pipe!

Managed to get the Lamda out of my old pipe and into the new one, but another sensor lower down on the bend.

Do not know what it is does, any ideas? I have blocked it off for now, but will I do any harm?

Car is a V4 STI

 

The sensor lower down is the 'cat on fire' sensor which is not needed - wrap the sensor out the way.

 

I cannot get the old sensor out of the old pipe so I have just dis-connected it from inside the inner wing, is this ok?

 

unplugging it from the loom is fine, maybe tape the open end over though.