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[cvobiker]

Other than a few mistakes there is one thing that most people do not know or understand and that article does not cover. That there are three types of sensors not two and MANY call the wrong sensor the wrong thing. Narrow Band, Broad Band and Wide Band are the three types, a TRUE wide band will do most of what that article states with a few exceptions but that is NOT what most use. DynoJet, DTT, Rev. and most (98%) other aftermarket AFR/Lambda gauges use a Broad Band sensor and you cannot confuse those results with a true Wide Band sensor which by the way is what they are describing in that article. A broad Band sensor is built using the same technology as a narrow band sensor and as Glens pointed out they are slower than a narrow band. They also cost about $50 bucks each, a true Wide band sensor is going to run you about $650.00 each........ BIG difference!

I love it when you get nervous...  It's funny as hell 

[HOGMIKE]

Full explanation of how the wide band works......summery on page 44.

Here: http://www.megamanual.com/PWC/LSU4.htm

 

[Steve Cole]

I love it when you get nervous...  It's funny as hell 

The only one nervous is the one that doesn't know any better. Funny how that works when someone comes along that real knows and tries to share it with people, how those that don't know come up with excuses.

[miker]

 

[glens]

Full explanation of how the wide band works...

Here: http://www.megamanual.com/PWC/LSU4.htm

Right under the included picture at the top, we read:

"Instead of switching back and forth from rich to lean, like conventional "narrow band" exhaust gas oxygen sensor designs, the wide-band sensor produces a signal that is directly proportional to the air/fuel ratio produced by the fuel injection controller."

Yes, the output of the sensor's controller does not "switch", but later on, about 2/3 down the page, close after the chart showing the relationships between major emission constituents at various AFR values, we read:

"To sense a wide range of air/fuel ratios, the oxygen pump uses a heated cathode and anode to pull some oxygen from the exhaust into a "diffusion" gap between the two components.  ... the Precision Wideband Controller measures the time when the reference cell passes through 0.45 volts.  It can then adjust the PWM timing to bracket this 0.45 volt stoichiometric flipping point."

It "brackets" the 0.45 volt flipping point.  In other words, its "loop" acts internally much like the closed-loop fuel control scheme in our ECM which drives its fuel both sides of targeted sensor output voltage, bracketing that voltage.  With our stock systems this could reliably occur on successive engine cycles only up to perhaps 2000 rpm (an engine cycle period of 60 ms).  The (stock) sensor element response time is rated at "<100  ms" for switching voltage from rich/lean either direction ( https://delphi.com/shared/pdf/ppd/sensors/mini-switching-oxygen-sensors.pdf ) which is about the same as the time indicated immediately after the first blurb I quoted above:  "The wide band oxygen sensor responds to changes in the air/fuel mixture in less than 100 milliseconds".  This serves to clearly illustrate that the "wideband" sensor's controller is indeed using its sensing element as the "switching sensor" that it is.  It's just coming at its conclusion from a different direction.  That document only states, however, that the sensor responds that quickly; not that the controller output does.

It seems obvious to me that you wouldn't want to use a bracketing closed-loop scheme on both the fuel injectors and a sensor's internal "pump" unless you could precisely synchronize them, else it could result in even wider swings than necessary.  A question naturally arises about checking one bracketing closed-loop system with a separate one: is it possible to find yourself obtaining only the high or only the low fueling swings while sampling closed-loop engine activity with an external probe?  At least at times?  Is it really safe to say "Wow, look at the crappy closed-loop AFR line I got off this TTS v-tuned bike!"?

[cvobiker]

The only one nervous is the one that doesn't know any better. Funny how that works when someone comes along that real knows and tries to share it with people, how those that don't know come up with excuses.

There ya go again.... Go read the first sentence in my post...

You're getting nervous again...  

[Steve Cole]

You posted part of an article that contains errors that you found on the internet somewhere and you want people to believe it's true. Sorry but it has errors in it and that's just why I pointed it out, still nothing to be nervous about at all.

[glens]

Yeah, I asked for attribution for that article, too.  I'd sure like to see what else the guy has to say, hahaha!

Brings to mind recently going through some "Dr. Dyno" articles he has posted at his site.  Oh My God I couldn't believe what I was reading.  And to think there are probably lots of folks who've "learned" all they know from such information...

[kraut]

this thread seems to deviate to a personal feud - I don't think we need this.

[Gearheadfmc]

Might be some personal slant.... but, I like to read about different views and opinions in this type of matter. Then formulate my own view.  So for me.... keep the points coming!

[glens]

http://www.enginebasics.com/EFI%20Tuning/AF%20Ratio%20Basics.html is where cvobiker found that article.  I waited long enough to find out so asked google instead.  The article ain't bad for a very basic overview to get started with.  I didn't look through any of the others there but suppose they're all about the same in that respect.