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im looking for an air/fuel gauge, and like the autometer one. but i heard that there are two different kinds of sensors, narrow and wide band. so i was sondering which gauge will allow me to use the stock sensor?
 

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anybody have any ideas? if anyone has an air/fuel gauge, i just wanna know what kind, and if i need to use an aftermarket sensor....
 

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The Autometer gauge, and any aftermarket A/F gauge, needs a wide-band sensor to operate properly. An aftermarket gauge wired to your narrow-band sensor will function, but it won't be accurate, and would be totally useless for actually tuning your engine.

Interesting that the later MkIV's are coming with a wide-band rear sensor from the factory...
 

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The Autometer gauge, and any aftermarket A/F gauge, needs a wide-band sensor to operate properly. An aftermarket gauge wired to your narrow-band sensor will function, but it won't be accurate, and would be totally useless for actually tuning your engine.

Interesting that the later MkIV's are coming with a wide-band rear sensor from the factory...

What kind of signal should i expect from the OEM sensor versus the wide-band?

How can i know if my gauge is not accurate?
 

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You cannot connect a wide-band O2 sensor to those types of A/F meters. Wide-band O2 sensors have a completely different output voltage range and must be closely temperature controlled and monitored be the measuring hardware. Narrowband O2 sensors, like their name implies, are accurate only within a very narrow range around 14.7:1 AFR. There's virtually no precision anywhere else in the AFR band. If you have a newer VW that has a wideband O2 stock (dunno which ones this is, but the wideband has 5 wires and the narrow band has 4 wires) you can get an accurate reading from an OBDII-logger, otherwise you'll need to install an aftermarket probe and reader. I use the one from http://www.innovatemotorsports.com/
 

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Rusty said:
The Autometer gauge, and any aftermarket A/F gauge, needs a wide-band sensor to operate properly. An aftermarket gauge wired to your narrow-band sensor will function, but it won't be accurate, and would be totally useless for actually tuning your engine.

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Its the other way around. They need a narow band sensor to operate. The autometer gauge won't even operate on a wideband sensor. Trust me. Iv'e tried. All it will do is one led will light up in the rich side, and thats it. No bouncing back and forth like it should. Only way for it to work properly is to install a narrow band o2 sensor.

edit- I just realized tha Macabre explained it in much greater detail than me!
 

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The Autometer gauge, and any aftermarket A/F gauge, needs a wide-band sensor to operate properly. An aftermarket gauge wired to your narrow-band sensor will function, but it won't be accurate, and would be totally useless for actually tuning your engine.

Interesting that the later MkIV's are coming with a wide-band rear sensor from the factory...

I think is the other way around

I read some articles and they all say the AFM gauge will read the narrow band not the wide-band

Dont believe me read this at Autometer
read the note on the bottom
http://hp.autometer.com/techtips/tech_writeups/air_fuel/air_fuel.html
 

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you beat me to it . ha ha :lol:
Rusty wrote:
The Autometer gauge, and any aftermarket A/F gauge, needs a wide-band sensor to operate properly. An aftermarket gauge wired to your narrow-band sensor will function, but it won't be accurate, and would be totally useless for actually tuning your engine.

.

Its the other way around. They need a narow band sensor to operate. The autometer gauge won't even operate on a wideband sensor. Trust me. Iv'e tried. All it will do is one led will light up in the rich side, and thats it. No bouncing back and forth like it should. Only way for it to work properly is to install a narrow band o2 sensor.

edit- I just realized tha Macabre explained it in much greater detail than me!
 

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:eek:h:

Well, I'll be dangnabbed! I should read up on things before I spout off on them... can anyone say ASSuME? :D
 

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Well, I'll be dangnabbed! I should read up on things before I spout off on them... can anyone say ASSuME?
Rusty you are actualy partially correct . i dont think you can use the sensor to tune your engine since it keeps bouncing back and forth
i installed mine and
it looks more like the night rider.
 

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Yeah, you can't fine-tune an engine with any narrow-band sensor. But I do have this VAG data correlated with A/F from a dyno run and I'm going to try...

http://www.clubb5.com/forums/viewtopic.php?t=67212

It looks like you need at least .9 volts to be anywhere near a good mixture at WOT. .95 is probably optimum for a high-boost engine. But this isn't as good as Mac's setup. Like was posted above, these voltages will vary with age of sensor and you can't tune precisely with this.
.
 

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[quote="1.8Tabamoura
Rusty you are actualy partially correct . i dont think you can use the sensor to tune your engine since it keeps bouncing back and forth
i installed mine and
it looks more like the night rider.[/quote]

That means your gauge is working properly, cause thats what the air/fuel ratio does. It constantly changes. From autometers web site.......

Since the oxygen sensor output is non-liner and very sensitive at the stoichiometric A/F ratio it will cause the A/F meter LED's to bounce back and forth rapidly. A very small change in A/F ratio causes a large change in oxygen sensor voltage as can be seen on the graph. This causes the A/F ratio meter LED's to rapidly cycle back and forth, and is normal operation when the PCM is in closed loop and trying to maintain a stoichiometric A/F ratio.



The oxygen sensor is very accurate at indicating a stoichiometric A/F ratio. It is also very accurate at indicating an A/F ratio that is richer or leaner than stoichiometric. However it can not indicate what exactly the A/F ratio is in the rich and lean areas due to the fact that the oxygen sensor output changes with the oxygen sensor temperature and wear. As the sensor temperature increases, the voltage output will decrease for a given A/F ratio in the rich area, and increase in the lean area as shown on the graph.

During wide open throttle (throttle opening greater than 80% as indicated by the throttle position sensor) the A/F ratio will be forced rich by the PCM for maximum power. During this time the oxygen sensor outputs a voltage that corresponds to a rich A/F ratio. But the PCM ignores the oxygen sensor signal because it is not accurate for indicating exactly what the A/F ratio is in this range. The PCM is now in open loop, and relies on factory programmed maps to calculate what the on time of the fuel injectors should be to provide a rich A/F ratio for maximum power. The A/F ratio meter should indicate rich during this time.

During hard deceleration the PCM will command an extremely lean mixture for lowest exhaust emissions. This may cause the A/F ratio meter not to indicate anything. The A/F ratio is so lean that it is outside the range that the meter will indicate.
 
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