Air/Fuel Ratio Gauge

[montazch]

Hello everyone.

I recently installed an Autometer Air/Fuel Ratio gauge on my 04 DTR. I used what I think is the lead wire on the driver's side upper oxygen sensor.

When I start, let it idle, or even drive/race, the gauge bounces back and forth between lean and rich. I doesn't settle down.

Has anyone else had this type of problem/bad luck? Anyone know how to fix this? Or was I really dumb and connected it up wrong?

Thanks for all your help!!

[Comin' in Hot]

I know that you need to install a 5th Oxygen sensor, because our car have narrow band O2 sensors and an A/F gauge needs to have a wide band O2 sensor.

[LANDY]

Explain what, when and how far the gauge is jumping.
They are supposed to jump around some depending on type of driving.

[montazch]

It jumps from total lean to total rich about every 0.8 seconds. Not quite a second in between and it is constant. It never stops. From idle to WOT. It doesn't matter what RPM.

[RF Overlord]

That is normal operation for a gauge on a narrow-band sensor. If you want a steady reading you need to install a wideband setup with a dedicated sensor for the gauge.

[montazch]

Ah Ha! It's amazing how AutoMeter fails to mention this. I'll get on that one. Thanks a million!!!

[Spectragod]

Originally Posted by montazch

Ah Ha! It's amazing how AutoMeter fails to mention this. I'll get on that one. Thanks a million!!!

When I ordered mine, it came with the additional 02 sensor and a bung to weld in.

[Pat]

I also have a narrow band A/F sensor, and watch the pretty lights dance from one end to the other on the gage face. At WOT the gage will go full green, otherwise it's registering the action of the O2 sensor. Thats good, tells you the sensor is working properly. Not for accuracy just fills the second space on my two gage pillar pod. The other spots is my BOOST gage.

[EMAS]

Of course Autometer isn't going to tell your that a narrow band sensor gauge is worthless on a vehicle that came with an O2 sensor from the factory and is only sort of useful on a carb equipped rig since they want to sell you the gauge.

You can think of the NB O2 sensor as a switch that only tells you rich or lean, not how rich or how lean, that is how the computer looks at it.

That is how the computer learns the fuel trim and controls the emissions. If it gets a lean signal it adds fuel until it gets a rich signal then it subtracts fuel until it gets a lean signal and does this all the time except at or near WOT. The catalytic converters need that to actually work. One part needs the extra oxygen and the other needs the un/partially burn fuel for it to start and maintain the reaction.

If you want to know the actual AF ratio you need a wide band sensor and it's corresponding gauge.

[BlackJack]

Good to know. Mine goes back and forth like a pendulum constantly as well.