View Full Version : What kind of output does a windeband O2 sensor give us?

08-09-2004, 01:59 PM
Is it an analog signal that could be monitored?

I read somewhere that it wasn't a straight voltage...

I was thinking of adding one, then I could wite some VB that would monitor it with an A/D converter....

Any input is appreciated!

08-09-2004, 04:52 PM
it is an analog voltage but you need a digital volt meter to read it,because its so minutte, It can be monitored,but must be monitored digitally,If you unplug your o2 sensor you should have 1 volt comming from the ecu.then when you plug it in and run you need to find the pin in the ecu block to measure the fuel ratio it should only vary 8 tenths. you can go to google look up (Ford eec III), or (K-Jetronics),(Lambda).
good luck ,Jim (Vetteman)

89 SC
76 vette
84 vette
87 vette
70 GT torino

08-09-2004, 05:36 PM
you cannot just plug in a wideband sensor and just read the voltage. Stock 02's are narrow band and have a reading from 0-1 volt where as a wideband has a voltage from 0-5volts. You need the controller in order to read the signal. This is why WB kits are so much, and the sensor is only about 60 bucks. I paided 500 bucks for mine but it also is a wireless datalogger.

08-09-2004, 05:55 PM
I'm not sure I get it.... I've read that you need some sort of controlle,r but according to this graph, there is simple direct relationship from volts to A/F...

unless this is the output of a controller itself...

My thought is to monitor that voltage using an Analog to Digital converter, and write a Visual Basic program to monitor and log this with a PC.

But are you saying that this output in the graph is a result of an already processed signal?


08-09-2004, 06:38 PM
yes...that signal has been already processed from the controller. Thats an analog wideband signal. The wideband sensor has 5 wires. its a completley different type of sensor. The stock sensor is just a 4 wire ( signal power, heater power, and two grounds) where the wideband sensor is a pump type sensor. I'm not sure what the 5 wire are used for, but you'd have a hard time hooking them up. In addition, the wiring harness used is special as well. the plug that connects the sensor to the harness ( that goes to a controller) is a funky looking connection. Its has a series of chips or resistors inside of it to allow for connectivity. If it was that easy to just tap a voltmeter into a wideband signal, everyone would have them. Believe me, i thought the same thing until i did some reasearch. You can get a PLX wideband unit with a display face for $330. Not a bad price or even the LM1 unit for $350.

08-09-2004, 09:39 PM
i just plugged my volt meter in to the black wire on my stock 02 sensor above .5 volts is rich below .5 volts is lean . it helped me a lot when i had my eec tuner working , and i could also tell it went into open loop around 4 pounds of boost it would go up to about .8 volts and stay there instead of going up and down trying to keep near.5 volts

08-09-2004, 10:10 PM
honestly....you CAN NOT tune you're car with the stock o2's. Stock o2's are only accurrate at 14.1-14.9 a/f. Which it roughly .8 volts. If you exceed that range, you'll get a standard voltage, but it wont tell you anything. If you are running at 12:1, it'll say .9 volts....if you are running 13:1 it will also say .9 volts. Bascially like i said, its pointless to tune with stock 02's. but the question in the post was what readings do wideband o2's give off. i'm not going to ramble on anymore about how you cant tune with a narrowband sensor...because this topic has already been discussed before and proven true.

08-09-2004, 10:21 PM
i know i dont know about wide band but i have to disagree i think mine stock 02 helped my tuning a lot . it really ripped when i leaned it out with the eec tuner to where it should be i could tell a big difference. i added a few degrees spark and shortened injector pulse width and turned up the air fuel ratio until it went below .8 volts at wide open

08-09-2004, 10:36 PM

here's my back-up statement

As you can see, when it reads about .9 volts it can be anywhere from 10.0-14.0 a/f, same thing goes on the lean side of the scale. Just stating that you're bascially guessing what air/fuel you're at and could cause major problems. This is just my opinion, but also backed up by facts rather than the "seat of the pants" feel. Anyways, i'm not trying to offend you in any way, just trying to get my point across. ;)

08-09-2004, 10:44 PM
Here's some info on the sensor and outputs, but you need a controller to handle the data.


This company sells the DIY kits: