Reading a Air/Fuel ratio gauge?

[MrPlow]

okay iv just install one in my ek4, im still trying the understand how to read it...

I dont understand why the leds bounce so much from left to right? and when i give it it moves to green (rich) and stays till i back off which then it goes to red for awhile - sometimes when its at red it goes blank for a second?

i always thought it stayed in the middle on the orange (stoich) moves either to lean or rich depending on your mixture?

[BLKCRX]

In short they don't work.. sell it.. and get your money back.
Your car use's a narrow band sensor in your car works as its either Rich or Lean, it does not give a accurate measure of your air/fuel or any negative feedback.

Even cheap wide band setups for 2000$ do not give full accurate measurements.... you need special tools to calibrate very special and expensive sensors, and correct testing equipment to be able to reliably say a sensor is accurate, without a standard the figures mean absolute nothing… iv even seen dyno wide bands change from dyno to dyno by as much as 20% due to sensors being abused dropped, and not calibrated. But in short the gauge you have is no more than eye candy. Measuring and tuning anything is always very expensive and always requires expensive tools


Regards James

[MrPlow]

Yeah sounds fair to me... i agree with the eye candy part - the thing doesn't stop boucning!

Just wanted to dress the interior up - but **** i was trying so hard to understand it last night - i gave up! It can always be removed - no drama!

[saxman]

narrowbands are worthless... wbo2.com makes some very nice wideband kits for a rather decent price. I've heard nothing but good things about them, use one myself, and have seen several people test using them and a wideband on a dyno and had same readings(obviously you have to calibrate it, but that's not that hard to do).

[sesshoumaru]

narrowbands are worthless... wbo2.com makes some very nice wideband kits for a rather decent price. I've heard nothing but good things about them, use one myself, and have seen several people test using them and a wideband on a dyno and had same readings(obviously you have to calibrate it, but that's not that hard to do).

saxman, being from the USA have u had any experience with the AEM wideband gauge??

From what i've read it's a wideband o2 sensor coupled with a digital gauge... was just wondering if this is as accurate as the wbo2.com range.

[BLKCRX]

Both those kits use the Bosh LSU sensor, which is wide band, but by far not true wide band , and does not support high temperature environments either, it does’t even come close when compared to commercial solutions used at some professional tuning workshops, which use sensors worth 50x more.



Regards James

[poid]

i know someone who did back to back testing between Autronic's UEGO wideband and the techedge WBO2 units and they were just as accurate. The Bosch sensor is quite a good unit and definitely accurate enough to tune off

[saxman]

saxman, being from the USA have u had any experience with the AEM wideband gauge??

From what i've read it's a wideband o2 sensor coupled with a digital gauge... was just wondering if this is as accurate as the wbo2.com range.
haven't personally used it... seems to be a case of works about the same as the techedge, just costs a bit more. Also, I believe the output is nonlinear which makes it a little bit more tricky to datalog with, depending on software

[ProECU]

OK firstly, you guys need to understand that a wideband gauge will NOT work if the sensor & controlling circuit are designed for narrowband output.
They "can" be accurate around stoich, in fact, it will be quite accurate within this range, however at both extremes, it will only tell you its either RICH or LEAN, but can not quantify it further.
Additionally, for those who care, the extreme gauge conditions is in fact due to the ECU. Short term O2 correction will cause the A/F ratio to cycle around lambda in closed loop. This is shown on the narrow band as a cycle from extreme rich to extreme lean, because of the inability to quantify as mentioned above.
Under Full throttle will be rich, and under when backed off the pedal, the ECU will infact CUT the injector pulse.

James is right in the high temperature department. The circuitry shuts the LSU sensors down over 700deg at a sustained time, for safety & sensor longevity.
Having said that however, they are extremely accurate and appear to be becoming the preferred standard. My local dyno shop uses this sensor and so do I with good success.
Accuracy & variation also comes from the way you wite it up to GND (white noise) and sensor placement before & after CAT so on so on...

Saxman is correct in mentioning that the voltage vs lambda equation is non-linear, however it is not any trickier to work with this. Manufacturers usually provide the mathematical equation to support this in software development, and even if they dont, simple mathematical manipulation of a system of piecewise linear bounded equations will yield a sufficiently accurate closed solution.
You dont need to worry about this if you dont develop software.

[saxman]

Saxman is correct in mentioning that the voltage vs lambda equation is non-linear, however it is not any trickier to work with this. Manufacturers usually provide the mathematical equation to support this in software development, and even if they dont, simple mathematical manipulation of a system of piecewise linear bounded equations will yield a sufficiently accurate closed solution.
You dont need to worry about this if you dont develop software.
I mentioned this because with some of the freeware softwares, they were having some issues with the aem wideband and getting it to read accurately. May have simply been a coding problem, just somethign to be aware of for those looking at buying a wideband.

[Weq]

James, id assume since most dyno operators use a sniffer, they negate the accuracy of there 10000 sensors?? being after the cat and all :P