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Slugman
08-07-2009, 04:02 PM
OK, I have searched etc - Found the ecu pinout info in Technical, but unfortunately it doesn't help me, or maybe it does & I'm just stupid today. A couple of hopefully quick questions;
Can anyone tell me what each of the 4 wires in the O2 sensor are for - Yes, I know that it has 2 grounds, a 5v signal & one to the ecu, but which way around for each of them? I don't want to end up putting 12v (or 5v) down the wrong way of a current loop, as I assume that it would be . . . bad.
Secondly, once I get the O2 operating, what sort of signal am I going to get out of it - I know that I am after an air-fuel ratio of 14.7:1, but what does that equate to?
I.E. I am going to get a value in the EMS Tuning display of "Insert bad number here" & I will need to auto-tune it to "Insert good number here".
Can anyone tell me what the "Good number" is? :(

I have a B18C5 Type R (I think - It's a 1999 JDM B18C), running with an EMS 8860 ecu.

string
08-07-2009, 04:51 PM
Not an answer, but a stock O2 sensor can pretty much only answer the question "Is the air-fuel ratio 14.7 or not". Tuning with a narrowband will only give you success in the columns you want to be 14.7 (idle range). The rest of the load columns will require a wideband O2 sensor to find the actual air-fuel ratio.

Slugman
08-07-2009, 05:03 PM
The ECU can (According to the instructions) be tuned by selecting the O2 reading value that I want, then telling the ECU to change the fuelling map to make it fit that value. Therefore if I wire it up correctly, then all I need to know is what the actual correct reading I want from the O2 sensor, & just tell the ECU to do it.

string
08-07-2009, 05:20 PM
The stock 4-wire O2 sensor can only tell you 14.7 or not, it won't give you an analog range coresponding to a range of air fuel ratios.

Slugman
09-07-2009, 10:39 AM
Found the info I am after - BlkCrx posted it in response to a question about "Running Rich" in the Technical Forum. Found it by searching for "Oxygen Sensor Voltage" :) - It was the 'voltage' bit that narrowed it down enough.
String - You might want to have a look at it . . . . I wish it was a sticky, but I guess that most of the people on here don't need the info. :o

CRXer
09-07-2009, 10:47 AM
Found the info I am after - BlkCrx posted it in response to a question about "Running Rich" in the Technical Forum. Found it by searching for "Oxygen Sensor Voltage" :) - It was the 'voltage' bit that narrowed it down enough.
String - You might want to have a look at it . . . . I wish it was a sticky, but I guess that most of the people on here don't need the info. :o
funny how u say the "voltage" bit "narrowed" it down......

string is right dude,stock narrowband O2 is useless to your purposes,unless u want to set a target lambda of 14.7 right across the board.........
not the best idea for WOT tuning.......

Slugman
09-07-2009, 12:09 PM
Um, yes - "Oxygen sensor" gave me 135 posts to trawl through, while "Oxygen sensor voltage" gave only 6. It is a narrower/more focussed search.

OK, so I guess I should also have asked;
Is the Primary heated O2 sensor on a B18C Type R (Located at the end of the header pipe before the cat) a Wide band or Narrow band sensor?

I.E. You are telling me about Narrow band sensors, while BlkCrx talks about Wide band ones, but what do I have? The info on Wide band ones gave no indication that they are are an extra modification - It gave me the impression that they are standard on Hondas.

CRXer
09-07-2009, 12:17 PM
ii meant "narrow" down the voltage,lol.

stock O2 is narrowband,ie its virtually an on/off switch,switching around stoic(14.7)

u will need an aftermarket wideband O2 kit to feed a more linear signal to the EMS,then u can set your target AFR's to what they should be at WOT/mid>high throttrle etc.
EMS will have a bitch of a time tryin to autotune around a virtual on/off switch in any case.

string
09-07-2009, 02:31 PM
Stock B-series O2 sensors are narrow band. They have a three state output: richer than 14.7:1, 14.7:1 and leaner than 14.7:1. This is insufficient information to tune fuel maps. You will need a wideband O2 sensor. Each manufacturer has different voltages coresponding to different a:f values but they are documented and graphs are available for all of them.

Limbo
09-07-2009, 02:49 PM
your gonna need a wide-band sensor if u wanna use that tunning display

Slugman
09-07-2009, 03:45 PM
*Sigh* :(

Thanks guys. I'm cranky, & about to be even more broke, but thanks for the info.
It just wasn't what I wanted to hear . . . . . :(

CRXer
09-07-2009, 04:16 PM
decent wideband & controller is only like $200-$300,u dont need a gauge if your datalogging the sensor,or even a cheap voltmeter u can hook up & just think of the AFR's in terms of volts.