Air/fuel ratio gauge

I didn't know these had gotten to be so cheap. I ordered one from Summit today to see if it'll help me get my 'pane setup tuned up right. Total cost was $70.80. Pretty cheap if it works as I expect.

SUM-G2986 A/F GAUGE ONLY BAR GRAPH
SUM-G2989 STANDARD O2 SENSOR
SUM-G2990 O2 SENSOR BUNG WELD-IN

It's a panel-mount 2-1/16" rich/lean air/fuel mixture indicator, low-end (no heat) O2 sensor, and a metric weld bung for the exhaust pipe.

I was gonna build my own indicator using a generic 02 sensor -- cause I was thinking the a/f mixture gauges were still a couple hundred bucks like they used to be. Glad I found this first.

They are cheaper now because everyone wants the more accurate wideband sensors and gauges. Mainly it's the import crowd using the wideband gauges because they are much more sensitive to changes and are necessary to tune the fuel maps on a high performance turbo or supercharged engines.

So for anyone who has actually installed and used an A/F gauge, do they actually work? I've never used one, but have been told by several mechanics/drag racers/carburetor specialists, that an A/F isn't accurate or isn't worth it and the true way of reading A/F ratio is to install a pyrometer in the exhaust and read EGT. How much truth is there to this?

I figure it's gotta be somewhat accurate - 02 sensors have been the backbone of computer engine management for quite a few years now.

That is a pretty good deal DP. You might want to find somebody with a FGA once you get your gauge installed. The FGA will give you percentage of all the exhaust gassess. Along with an exact air fuel ratio at the tail pipe. This way you will have a number to associate the "rich" and "lean" readings the gauge gives you. Kind of like using an infrared thermometer. You have to establish a base for the component you are watching before you know what is too hot or cold.