I've been doing some homework on this item and it appears that wide-band 02 sensors are 5 or 6 wire units. While 4 and 3 wire uints are narrow band 02 sensors. I've been logging the mv 02 signal from my stock ecu and stock 02 sensor and from all the dam jumping that I see it looks like it's a narrow band sensor and the ecu just counts the frequency of the cross-overs from rich to lean to figure out what to do with the injector frequency and the timing.

Anyone have some facts on this?

 

The 2nd o2 sensor (on s pipe underneath the car) is a narrow band while the 1st sensor (the one on the header and you can see under the hood) is actually a wideband. It is limited but still sees more ratios then a narrow band. Currently I don’t think anyone knows how to view the ratio and I do not know of a scan tool that can view the ratios but you could give this site a try (http://www.autoshop101.com/forms/h37.pdf) and look on page 6 (figure 2-79). It has the output for the wideband and I think this is for all wideband sensors for Toyota’s. I believe 3.3 volts is 14.7 AFR. If you have more questions on o2 sensors you could always just read the rest of that PDF.

I was wondering if there was a way we could make a box that could data log the o2 voltage without affecting the actual output to the ecu. It would be nice to use the stock sensor for a cheap way to log AFR’s. I know Underdog Racing has experience with Toyota wideband sensors. They have a product (http://www.urdusa.com/product_info.p..._id=1230100028) already for altering the o2 sensor voltage for tuning during closed loop operation for Toyota vehicles. You may want to give them a call for information. Anyways I hope some of this ranting was of some help.

 

primary is a 4 wire wide band. secondary isalso 4 wire, not wide band. Primary will run you 324 from autozone (2002 camry), secondary will run you 156.

 

your a genious im getting my plx-m300 in 4 weeks and i have an obd scaner that monitors the voltage on the o2 sensors

i can log them both i think we can figure this out

 

http://hopupracing.com/grininfcosh.html
this looks like it could be usefull (if it works).

 

they look nice but my obdII scanner does all that well most of it

 

I've been logging my OBD2 data stream -but it appears that the 02 sensor that I tap into is the narrow band 02 placed after the cat. The sensor output and the response is very close to a text-book narrow band bosch sensor.

 

Which obdII scanner do you have aarontrini85?? I just have some cheap scan tool (it uses scantool.net ELM scan tool connector) and I can only see the 2nd o2 at least with the software I have. I am currently looking at getting a plx r-500 because I would like to tune my tC (current has a zpi stage 0 soon to be stage 1 hopefully), DSM, and my friend has a civic he is currently modding. I figure it would be better if I could log more. I was hoping I could possibly make a display for the stock wideband o2 or maybe even a data logger for afr's. Maybe if you could log o2 voltages then maybe you could use you plx m-300 to verify the voltage and afr's and maybe come up with our own graph. I might make a display as a project for my electronics class (I am an Electrical Engineer major) since I need a project for class soon. This could be very interesting if we could get accurate afr’s out of the stock wideband.

 

don't buy from hopupracing.. I had a bad experience with them and so did several people on evolutionm..

 

awww fawk if its the 2nd sensor il still know how i can do it but it will suck with a multimetter and a pen lol

 

This is the data that I can get through the ODB2 and the datatap scanner system

Short Term Fuel Trim Bank 1(%)
Long Term Fuel Trim Bank 1(%)
Short Term Fuel Trim from O2 Bank 1 Sensor 2(%)
O2 Sensor - Bank 1 Sensor 2 (mV)
Throttle Position Angle(%)
Vehicle Speed(MPH)
Calculated Engine Load(%)
Engine Coolant Temperature(°F)
Engine Speed(RPM)
Fuel System Status Bank 1(NO UNITS)
Ignition Timing Advance(Deg)
Intake Air Temperature(°F)
Mass Air Flow Rate(lb/min)

If you log all the data it takes about 2 seconds to go through all of them. If you log 5 then you get it all in less than a second.

I get about 7 more points that are text based -but this is about all that I've found. The fuel trim numbers do not seem to follow any good pattern. I need to find a look up table to convert the data into a more usable form.

Hope this helps

 

The short term fuel trim might be directly related to the front o2 sensor. I can not really verify this until I get a wideband but it may be possible to convert the short term fuel % into an afr... just an idea.