sh!ft

came across this on honda swap

If you bought a CX or DX civic with a 1-wire o2 sensor, you're going to have to convert to a 4-wire to run a b-seires ecu, and most of the "top of the line" d-series ecu's like the p28.

First things first, you need to physically buy a 4-wire o2 sensor. you can't send a heater signal to a device which has no heater circuitry and expect it to work


Wires on 4 wire O2:

WHITE: Signal Wire
GREEN: Signal Ground
2 BLACK: Both black wires are the heater circuit wires.

Using a P28 ECU (and should work for most obd1 ecu's with 4-wire controls)

Run O2 Sensor signal (white) To D14
Run O2 Sensor signal Ground (green) to D22 (or any good Ground)
Run O2 Sensor Heater Circuit Control (black) to A6
Run the other black heater circuit power wire to (A25) or any good switched +12VDC source.

(you may mix up the black wires... if car dies after it is warm/10-30 seconds, that's the first thing to swap over and troubleshoot.. theres no way to tell one from the other by looking at them)

Clipsed

iTrader: (2)

that's cool, but this info is in the faq.

blasterman87

thaught all obd0 was 1 wire? mine is/was

black0hatch

ya obd0 is 1 wire.

USDM sI

cool... but how the hell do you wire a 4 wire to 1 wire (obd0 to obd1)

DCRB

that's easy. just pin the signal wire into the single o2 sensor plug and ignore the rest.

USDM sI

wish it was tht easy... wouldnt that be nice ha
just did tha earlier tonight didnt help squat

TJChad

Then that either wasnt your problem or you still tried to use the 4 wire O2 which won't work. If you are using a single wire 02 ECU then you must have a one wire sensor.

USDM sI

i have a four wire ECU and am trying to use a one wire sensor
noones ever tried this b4??

TJChad

The signals that the two different sensors send to the ECU will be MUCH different. It shouldn't work. If you have a 1 wire ECU you need a 1 wire sensor. If you have a 4 wire ECU you need a 4 wire O2. The same thing goes for people thinking that they can wire 2 O2 sensors to the same port on the ECU. If you understand how O2 sensors actually work, they are not the same and will not work.

b16racereg6

iTrader: (2)

good easy write up

USDM sI

4 WIRE ecu and i was trying a 1 WIRE o2 but no it doesnt work