i just bought an autometer air fuel ratio gauge and was just wondering if it mattered which o2 sensor i hooked it to.. gotta love obd-II

Use the front one.
The back one won't show much if your catalytic is working properly.

yes , i figured the front one would be the best .. just wanted to make sure before i go tapping into wires tomorrow morning.. thanks for the input

No, it doesn't matter which O2 sensor you plug the gauge into

Neither one will read A/F ratio accurately

Originally posted by ClassicSE-R
No, it doesn't matter which O2 sensor you plug the gauge into

Neither one will read A/F ratio accurately

it'll read accurately for a .5 :rolleyes: but you can hardly call that "accurate"

you really need a wideband for tuning. the air/fuel guage reading your o2 sensors is going to be more annoying than helpful

Tap into the white wire on the front O2 sensor. It won't tell you anything about the way your car is running, but this is the "correct" signal wire to connect to in order to get the gauge to move around like it should :-)

Or, you can connect the wire to the correct terminal behind the ECU.

Good luck,

Originally posted by jon3k


it'll read accurately for a .5 :rolleyes: but you can hardly call that "accurate"


It's not even that good.

It should be good enough to tell whether you are running rich or lean though. Other than that mine doesn't tell me anything.