i have a 1991 honda civic dx hatch in the center of the fire wall a little closer to the drivers side is this...

and heres a little closer picture...

when i had to take the dash off it wasent connected to anything under there eathier but im gunna be doing a b18b1 swap no a/c or anything just heat so if someone can let me know if i should remover it or what it might be for it would be appreciated thanks.

 

That's your speedo cable. Use depends on the cluster gauge you plan to use. Plugs into the transmission. Normally routes through the firewall (grommet is missing), behind the heater box (center of dash) to the driverside, up into the cluster gauge area and into the back of the cluster itself.

 

alright thanks for the input man