Ready to do some tuning and need to get a handle on the Air/Fuel ratio. I decided to go with a wide band sensor and reader/measurement device so I can get more granularity than the narrow band option.

I am wondering what people may be already useing for wide band O2 measurement?

I am competent with electronics, so I am considering the TechEdge Wide Band O2 (version 2.0) kit with the Bosch 6 066 sensor?

Any other systems I should consider?

I am assuming the sensor should go downstream of the collector (to where temperatures are tolerable), but on the motor side of the cat?

 

Yes, motor side of the cat. I've bee waiting for the 2.0 to come out. Looks like it is here.

 

Please forgive my ignorance on the subject, but what is so special about this unit? Why pay $650 for (from what I can gather) is just a monitor when you could get an A/F controller for $300 or so? ...or can the TE do what an S-AFC could do - and if so what kind of advantages does the TE have over it?

 

These are two different devices for different purposes.


The TE is purely a monitoring device (effectively a gauge) that leverages a newer oxygen sensor technology to see and measure a wider range of air/fuel ratios (i.e. wide band) than earlier technologies (narrow band) which aren't very effective at telling you how far away from "normal" you are, and typically just send a signal of "too high" or "too low".

The TE device would normally be used as a piece of tuning hardware so you can do things like, run a little richer during peak boost with an S/C, etc.

The S-AFC is a controller. It does not do any actual measurement of A/F ratios, but instead reads the Intake Manifold Pressure, Air Flow Capacity, Karmann Frequency, Engine RPM, Throttle Position, and Air Flow Correction %. It uses those characteristics to make changes to the MAP sensor signal to "fool" the ECU.

With the S-AFC (or any piggyback that doesn't directly read the O2 sensor or is using an older style O2 sensor) you would still want some type of device to measure your actual A/F ratio to provide it with the right codes to offset the values going to the ECU.

There are a couple of good diagrams on the TE site showing the characteristics of the newer wide band sensors which compare the signal and sensitivity of thresholds compared to the older narrow band sensors.

http://techedge.com.au/vehicle/wbo2/wblambda.htm
http://techedge.com.au/vehicle/wbo2/wbntk.htm

Short answer is, one is a controller, the other is a measurement device. The wide band sensor gives you more data to be able to more precisely tune a piggyback or full engine management system for modifications.

Hopefully I haven't misused any terms. Others please correct me if I have mispoken in any way.

 

So essentially, the S-AFC is in a matter of speaking, a cheap shortcut or a bandaid to adjusting the A/F ratio, while the TE gives you a much higher level of data to actually do the job right. Is that far off? Since the TE is only a sensor/data collection unit, what kind of tool would you use to finally adjust the ratio? SMT-6? Or is that just another "bandaid" since it alters the maps also? Thanks for bearing with me and my probably stupid questions - just trying to learn as much as possible since I've never seen this type of thing before!

 

Has anyone thought about if the newer trucks and 4Runner's wide band O2 sensor would work on our older 96-98 4Runners?

Chris

 

Your questions are very fair, no worries. The TE is exactly as you described, a tool to measure the actual A/F ratios.

The S-AFC, SMT or FTC (which I am using) are required to make adjustments to the ECU (including timing, A/F mixtures, etc).

It isn't a matter of one being better than the other. One measures, the other adjusts.

Regardless of which products are used, you need both functions: tools to measure and tools to adjust. Expect to see piggyback units like the AFC, SMT, etc to keep getting smarter. There is no reason why they couldn't integrate the technologies so you could define things like the A/F mixture across various RPM, Manifold Pressures, etc and make the adjustments automatically.

Hope this helps.

 

Chris,

How did you dial in your larger injectors and SMT? Did you use a narrow band A/F sensor/gauge or did you go to a dyno?

Thanks!

 

It's dialed in using my stock O2 sensor, the SMT-6 Software, and the BR-3 to check the short and long-term fuel trim. Supposably, I really need a wide band to properly tune it, but they sure are a lot of money, and I was thinking it could be a lot cheaper to pick a new truck (what years?) wide band from a junk yard for cheap if I knew they would work.

Chris

 

Thanks Derrick, I think I've got a good handle on what's going on now.

 

Derrick:

Some other wideband sensors are the FJO, Autronic (sorry no link), and MOTEC. I believe AEM has also released a wideband sensor, but I think it integrates with their EMS system and is not a standalone. All very nice systems but very expensive.

Another option, if you are electronically competant is the DIY WB. I just built/tested one and it's pretty accurate compared to the Motec wideband at the dyno although the response time is a bit slower.

Now I just need to build a display for it

 

Chris:

The wideband o2 sensor doesn't necessarily have to work with the car for you to use it ... just weld it in and hook it directly up to a unit like the TechEdge, but leave your existing o2 sensor in place.

I did that with an NTK wideband o2 sensor rather than worrying if it would work with the ECU or not.

 

Trangk,

I was hoping for a permanent unit by replacing the original O2 sensor with a wide band from one of the newer trucks. Who knows, but maybe someone has already tried it. Does anyone know what year the 4Runners and Tacomas went to a WB O2?

Chris

 

Chris-

I'm not sure if the newer O2 sensors are WB, but if they are they require a controller to understand the signal they produce and run the O2 sensor so it maintains a constant temp. It would require a lot of work figuring it out and I think that may be the reason a newer ESC hasn't been released for the new trucks.

Derrick-

I have an FJO and am very happy with it. I don't have any experience with the other brands or DIY ones so I can't compare them. If you get a DIY one make sure you buy the sensor first because there was a nationwide shortage of the sensors.