Originally Posted by 95naSTA
A narrow band O2 gauge will only give you a light show. It'* no where near as accurate as a wideband.
The narrow band is useful, but just as a cross check for WOT only. I use it for comparative purposes. For example, on a normal WOT pass on the bottle, I see one to two orange bars above the green on the A/F gauge (about 0.900 volts on the scan tool.) Changing the jet size up or down by two jet sizes on the fuel side runs the A/F gauge too rich or lean. Three jet sizes is about off the scale. So, for my purposes the gauge is good enough and can be checked with a glance while making the pass. You just have to be in the ballpark first and understand it'* limitations.
It is better than my old method of tuning a nitrous motor...i.e. running it way rich on the fuel jet, seeing how far down the track the motor will pull before getting flooded with gas, then backing down a jet and repeating until the car pulls the entire quarter without flodding the motor.
Btw, anybody else remember the old A/F gauges that were factory options from GM? (think back to the mid 70'*...GM was putting "Fuel Economy" gauges in the dash...it was just an analog A/F gauge marked for fuel usage.) If ya want a really cheap A/F gauge for your car, dig one of those out of, say a 1976 Grand Prix or Monte Carlo. Or, just get a junk voltmeter and remark the scale.