How do i wire a 4 wire o2 sensor in my dx with b18b!?

[Thewhitecivic]

Does anyone know how to wire up 4 wire o2 sensor on 91 honda civic dx
it currently has the original 1 wire o2 sensor i need to wire up the 4 wire for the b18b swap

im always using the universal bosch 4 wire o2 sensor it has 2 white wires and 1 gray and 1 black

please someone help and tell me how to wire this thing up it frustrating lol

 

[RonJ]

Go to the Bosch site. It should have the wire codes. My guess is that the 2 white wires are for the heater and the other two are for the sensor, but do verify.

 

[Thewhitecivic]

yes the 2 white ones are heater
the gray one is ground(12v ignition)
and the black one is signal for the ecu

 

[RonJ]

the gray one is ground(12v ignition)
and the black one is signal for the ecu

Only the heater element receives voltage via the ignition switch. Neither O2 sensor wire does and both pin to the ECU.