Stock 02 oxygen sensor is 4-wire

[ERIC-TC]

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?

[OuterHeaven]

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.php?cPath=66_72&products_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.

[l3rl4n]

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.

:)

[aarontrini85]

OuterHeaven wrote: 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.php?cPath=66_72&products_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.


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

[jjos1]

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

[aarontrini85]

jjos1 wrote: 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

[ERIC-TC]

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.

[OuterHeaven]

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.

[DouBLeJ16]

jjos1 wrote: http://hopupracing.com/grininfcosh.html
this looks like it could be usefull (if it works).

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

[aarontrini85]

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

[ERIC-TC]

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

[OuterHeaven]

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.