I saw a air/fuel ratio gauge at Discount Auto Parts;
I did not get it because you need to splice into the O2 sensor wire from the cat.
I felt that adding/subtracting resistance or changing the Ohms sent by the O2 sensor would mess up the ECU.
Any thoughts on that; or do other "wide band" gauges get around splicing the O2 sensor?

Am I misunderstanding my O2 sensor or ECU; or am I just under-estimating the "Wide Band" gauge maker?

Thanks.

Your OEM wide band is not 'normal'. It's a current based usnit specifically for the RX-8 and its ECU. You can add another one, but it would be completely independent of what's there.

I saw a air/fuel ratio gauge at Discount Auto Parts;
I did not get it because you need to splice into the O2 sensor wire from the cat.
I felt that adding/subtracting resistance or changing the Ohms sent by the O2 sensor would mess up the ECU.
Any thoughts on that; or do other "wide band" gauges get around splicing the O2 sensor?

Am I misunderstanding my O2 sensor or ECU; or am I just under-estimating the "Wide Band" gauge maker?

Thanks.

The gauge you saw was a narrow band if it only splices into the signal from the O2 sensor and no it is not enough to change the signal to your ECU. Although your O2 sensor is wideband you would be reading an unadjusted signal from only one of the wires which is in effect like a narrow band O2, not as accurate because it doesn't compensate for temps etc. When you buy an aftermarket wideband gauge it usually comes with its own wideband sensor that you have to weld a bung for on the exhaust somewhere, it also brings its own little "computer" that controls a heating element to keep the O2 sensor reading consistently no matter the circumstances as well as calibrates the sensor for accuracy. The gauge manufacturer probably says that it works with both narrow and wide band sensors, and it does, but it is still a narrow band reading you will be getting no matter what.

Hope this helps

Chris

p.s. check out innovate, aem and a few others that make true wideband meters....