is this an important part or can it be removed. I ask this as i have fitted an after market manifold and have no where for the wire to go

 

The Oxegen or Air fuel ratio sensor, is that what you are refering to?

 

yeah thats it

 

it should screw into the 02 housing. But seeing as youo have an FQ-300...there is no way for us in the states to know about that. But generally the #1 O2 sensor is the primary and yes....you need it. This is only speculation as your car is unique.