Ok i have been doing tons of searching for how to wire up a wideband to a p28 but have found no results for my specific application. Last summer I rebuilt my d16a6 and did the mini-me (d16z6) , upon doing so I had the idea of boosting in the back of my head, so instead of blowing 90$ on a 4 wire o2 sensor i just left the stock A6 o2 1 wire in because i knew i would be purchasing a wideband in the near future. Well that time has come, I will be buying an AEM UEGO wideband shortly but want to be 100% sure on the wiring before I make my purchase. I understand so far that the stock ecu only reads narrowband (0-1v ?), and that most widebands have a switch that can send narrowband information to the ecu (I plan on replacing the single stock o2 with the wideband because I would rather not have another bung installed, but may result to this if the answers received deem it the best option). But which of the four stock wires for the p28 o2 sensor go to the wideband? Any help, or direction to a writeup would be greatly appreciated, note: I am not currently running any datalogging or engine tuning (chrome, hondata, ect).

 

the wideband is entirely seperate from the ecu. It's purpose is to display accurate air fuels, and those numbers are used to tune. It has the capability of outputting a signal that can be interpreted by data loggers and/or engine management systems like an aem ems. whether that analog output would work with the stock ecu as a narrowband input i cannot say, but i would imagine not.

 

I am pretty sure that you need to run the 4 wire o2 for the ECU, and then use the wideband for tuning. go to a junkyard and grab 1-2 of the 4 wire o2's. i know near me they only charge like $5 for o2 sensors so if it doesnt work, its only $5 lost.

 

It can work that way. My son ran one that way in his OBD1 P30 CRX B16A swap, he is currently running one in his OBD0 PR4 CRX LS swap and he will be running one with his new OBD1 P30 CRX GSR swap.

I am also running it that way in my blown OBD2 96 Mustang Cobra. We both are using the old PLX M300s, but most of the modern WBs have a NB output that will work.

With an OBD0 ECU, you can just run the NB output of the WB to the ECU's O2 sensor signal wire. With an OBD1 ECU, you run the NB signal to the ECU's O2 sensor signal wire, but you also need to put in a resistor across the O2 Sensor Heater wires in order to fool the ECU into thinking that there is an actual 4 wire O2 sensor there when it tests the heater circuit. If you don't, you will get an O2 sensor heater failure CEL. I can't remember the resistor values for either car. I'll keep digging for that for you. We may be able to find it on pgmfi.org too.

FYI, the 4th wire is signal ground. Make sure you have good ground connections everywhere.

It works very well for us, although I do notice a slight phase difference between banks on my Cobra, so there may be a slight timing change. The phase difference doesn't affect anything on the Cobra. Since your engine is not a V8, you won't even notice this.

 

I found it. You need a 1K Ohm, 1/4 Watt resistor for Honda OBD1 computers. FYI, for OBD2 SN95 Mustangs, it needs to be a 20 Ohm, 10 Watt resistor.

 

Thanks Mark, do i place the resistor inbetween the WB and the stock wires to the heater cables? The way the pictures look for the WB kits the sensor has a plug that plugs into wires leading to the WB gauge and other goodies, should I spilice in the Engine harness with resistors to the two heater wires on the WB?