I have a 92 eg hb with a JDM D15B engine and a P28 ECU. The check engine light is on and it is throwing a code 41(O2 sensor). Everyone local is telling me I have the wrong O2 sensor in there. They say I should have a 4 wire instead of a 1 wire. If so, how do I go about wiring in a 4 wire O2 sensor? or can I make the one I have work. Also am I doing any damage to the engine driving it with this?
Thanks in advance.

 

Driving with the O2 CEL on is just making you run rich all the time. Not really bad for your car, but can be murder no gas mileage.

For the 4 wire O2 sensor, you basically need to wire in a plug so that your sensor feed goes to the ECU, you have 2 reference grounds and the 4th wire is for heating the O2, but I'm not sure how much voltage that requires.

 

Any more details would be great. Can I use the existing O2 wire to connect that to the ecu then make two grounds and finally find the pin on the ecu that is for heating the O2 sensor. Or is there a power supply that i need to tap into for heating? A little more info would be great

 

Code 41 is for the electric pre-heater that's built into a 4-wire O2 sensor. The only thing that's good for is heating it up so it begins working sooner when you start your engine. You could get a 4-wire sensor & wire it up properly...

Or you could fool your ECU into thinking that it has a sensor heater. Get a 30-ohm resistor (10 watts or more) & wire it into the heater circuit.

The heater circuit gets constant +12v from the main relay when the car's turned on. The ECU closes the ground side of the heater circuit when it wants the heater to be on.

 

OK, I got your PM, but I had to come back here anyway to check what stuff you have...

The wires on a 4-wire O2 sensor are for:
1) O2 sensor signal
2) O2 sensor ground
3) +12v supply from main relay, or from ANYWHERE that's live
4) heater circuit ground side - the ECM closes this to ground when it wants to turn on the heater.

I don't know which terminal on your ECM. You'll have to get a circuit drawing (Helm book?) for the car your ECM came from. I wouldn't trust that it's the same for all different years/cars. So I guess I can't REALLY answer your question. The heater circuit (#4 in my list) is A6 (orange/black) in my '95 GS-R. The sensor signal is D14 (white/red). But I'm not confident it's the same for different years.

 

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-PHiZ