Due to some issues with CO and emissions I gotta change my lambda from a 1 wire in a single runner on a 4-2-1 stainless manifold to a 4 wire after the collector. It has the bung there but I have to make the wiring myself with a switch for the heater portion of the 4 wire. Not hard to do. What I do wonder is which 4 wire lambda I should get. There are many of them for Honda lol. I'm using a '97 EK 4 door with a EUDM D15Z6 motor. 4-2-1 Mani + SRS 200 cell high flow cat + 2.25" to the back with a universal Supersprint muffler. It has a CAI as well as a D16Y8 intake mani with stock D15 injectors but no other mods for now. The 1 wire now only sees one cilinder per cycle so it doesn't read properly and just thinks it runs super lean so adds fuel or doesn't respond at all. The values on the Hondash are very slow and all over the place. So, TL;DR, What model / part number 4 wire lambda do I need for a 1 wire to 4 wire conversion on a EUDM D15Z6 Civic EK?

 

Bump.

I really need to know for the MOT.

I am assuming with some research done that this is the correct one? (Local Honda specialist shop)

https://www.a4h-tech.com/nl/oem-hond...ensor-4-draads
​​​​​​It's a Denso 4 wire for many models of Honda from the same era so it should be correct for the conversion right?

Which wire colors are what function? So signal - gnd - heat - gnd heat I assume?

 

Why do you believe that a 4-wire O2 sensor will provide better emissions than a single-wire O2 sensor ? If your single-wire O2 sensor is mounted within 8 inches from the cylinder head, the exhaust gas warms the sensor to the proper operating temperature. When you mount an O2 sensor further away from the cylinder head than this, like in the rear of the header collector as many Honda/Acura models did beginning in the mid 90's, a heater element is required to warm the sensor to operating temperature because the exhaust gas has cooled below 600'F at that point and cannot warm the sensor directly.

 

If for whatever reason you are still inclined to install a 4-wire O2 sensor, here is your wiring requirements:

White (White/Red in some cases) wire: O2 signal output wire
Green/White wire: O2 signal ground
Orange/Black wire: Heater control ground from ECU.
Yellow/Black or (Black/Yellow): 12v+ for heater control circuit

The White and Orange/Black wires connect to points at the ECU. These locations will vary depending on what your ECU plugs look like, so I will not provide exact locations. The Green/White wire can be connected directly to the ECU, or if you want to keep it as short as possible, it is shared with the IAT, ECT, and TPS wires of the same color. It can be tapped into any of those. The Yellow/Black (Black/Yellow) wire can be connected to a switched 12v+ wire... a good choice would be the same colored wire at the Purge/Cut/EVAP sensor.

Good Luck.

 

Thanks! The reason I wanna swap to a 4 wire is because the bung after the collector part (still pre-cat) is quite far downstream in the header so it's much further then 8 inches and will not heat up properly. And I need it to properly read all 4 cilinders in stead of just one like it is now because it thinks it's running extremely lean due to only 1 cilinder combustion being measured and thus throws fuel at it and makes lambda and CO too high.

 

Does you ECU support a 4 wire? The heater circuit is controller by the ECU to hit and maintain that temperature target. It is not just a turn it on and let it eat heater. The ECU does pulse width modulation to keep the sensor at the optimal temperature.

 

Not sure, the D15Z6 EUDM I have uses a P2Y ECU. I was planning to go full D16Y8 swap + programmable ECU (either a P28 or similar or a S300), so IM, TB (or B16A2 TB), sensors, cams, bridge and VTEC solenoid to basically build a D15Y8 but I am having a hard time finding the parts. I have the full intake manifold with sensors but no TB (it came with a D14A4 one), no fuel rail, no injectors, no cams and bridge yet (or a whole head to harvest them from) so..

But yeah, I run the P2Y for now. Not a clue if it can. The heater will not be used during normal driving, only forcing it for the emission test which is yearly.

 

If that is your plan, grab a wideband sensor that has a auxiliary narrowband output. Wire the narrowband output to the ECU and call it a day. The sensor will take care of the heater and give you wideband capability when you go to tuning.