I want to be able to monitor my air fuel mixture and i have seen gauges for wideband and narrow band o2 sensors. Will a gauge for narrow band work fine for just monitoring. Can't afford a wideband O2 right at the moment.

 

It will give you an 'idea' of what your air to fuel ratio is. I used to have a narrow-band... I got rid of it. Still don't have money for a wideband, but I plan to get one eventually. The only thing the narrow-band ever did for me was make me more anxious about whether or not I was REALLY running a legit air/fuel ratio. You can also use a multimeter to check your air/fuel ratios. (Similar to a narrow-band. Not as convenient.)

 

A narrow band gauge is a joke.(disco light special)
a wideband is functional.

 

Maybe I'm mistaken, but I was assuming the stock O2 is narrowband. is it something totally different? I'm assuming a wideband most give a much more accurate reading.

I'm interested in hearing the method for reading air fuel mixture with multimeter. I would really like to get an idea before I go driving it a lot.

 

A specific O2 sensor voltage gives you a basic idea of your air to fuel ratio.

(Found the information below on a Datsun forum. It is still relevant, though.)

Volts > A/F ratio

.1 > 17:1
.2 > 16.5
.3 > 16:1
.4 > 15.4
.5 > 14.9
.6 > 14.4
.7 > 13.8
.8 > 13.2
.9 > 12.7
.985 > 12.1

 

save up them pennies and get yourself a wideband. totally not worth getting a narrowband.

 

A narrow band is only a "joke" if the user doesn't know how to interpret it.

Sure, it won't give a very good exact ratio, but it will let you know if the car is grossly rich/lean, if it's in closed loop, if the aux air system is functioning, and will teach you how to drive economically.

Now obviously these functions are only really useful in a stock car, and if you are modified, then a wideband will be the better choice, especially if you intend to use it as a reference for tuning.

Something to consider is that cheap widebands have really only been on the market since the late '90s. Before then, tuning was done by reading plugs, EGTs, narrowbands and smell.

 

Okay thank You Guys. So what is the optimal air fuel ratio I should have. at idle and when excelerating. for now I'll go ahead and hook up my voltage meter to it so I have an idea. Sonn as I can afford it I'll get a wideband o2

 

Just saying that the Wideband will actually give you the air fuel ratio numbers and the narrow band will give you Nothing but Rich/Lean indication.
It will be flashing lights on and off all day long,and what would that tell you?.Nothing.
..I mean seriously, when was the last time you heard someone say that the car was running one red light then it flashed 3 green ones on acceleration then suddenly went back to 2 red lights,when they were explaining their fuel/air ratio?.
If you want a gauge that will be useful then get a wideband gauge.
Otherwise it would be like upgrading your cassette player to an 8 track.

 

on an S4 NA with stock ECU and all the emissions, with a wideband you will see

idle - 16-18:1, the air pump air is injected BEFORE the o2, the engine is running at more like 12-12.5:1
1100rpm to about 3500rpm - 14.7 closed loop
WOT over 3500, it'll start around 12.2 lean out a tad and then go richer.

on an S5 with stock ECU and all the emissions

idle is about 18:1
1100-3500rpm its 14.7 closed loop
WOT over 3500, is 12.2, but it gradually richens up to about 11:1.

 

It will tell you all that stuff I mentioned in my post.

Narrowbands have their uses, though of course a wideband is ideal for tuning.

It's best to ask why the person needs an A/F gauge anyway. If it's a stock car, then a wideband won't be much help except at WOT due to the aux air system.