Wiring up a new o2 sensor today (4 wire universal)

hoping you guys could tell me which wire on the OEM o2 harness is the signal,heater wires. The directions with the new sensor and crap. Is the wire running from the o2 sensor back to the ECU the signal wire?

can anybody help please?

 

For the '94-'95:

B/Y = Heater +12
B = Heater GND
R/L = signal + (goes to ECU 2N)
B/L = signal GND (goes to ECU 2D, along with the MAF, CLT, EGR and TPS sensor grounds)

 

and on the sensor

white - heaters
grey - ground
black - signal

 

Does the same wiring config apply to the 90-93's when putting in a 4-wire 02 sensor? I can't remember, but there is some ref somewhere about a 4-wire sensor and wiring up a Bipes?? I am less sure of what the reasoning for the 4-wire in the 90-93's would accomplish, but I do remember that using one DID have some beneficial purpose.