stoich meter

[qikr33]

has anyone hooked up a auto-meter air/fuel guage are they any good?i heard they are all over the place .any ideas would be great ,and does this just hook up to oxygen sensor??any info will give u 1 year good luch

[blind_elk]

They're supposed to be all over the place - the A/F is constantly changing in response to the ECU's attempts to maintain stoichiometric running.

[CMS Drifter]

have heard they are good and easy to fit. just hook up to ig power, earth and the white wire from th oxy sensor.

[skylineakt]

I had a Autometer AF ratio meter installed not long ago. They look great and yeah there is only 3 wires that needs to be connected up (4 wires for the Cobalt series, for backlight).

When cruising, my one runs back and forth between lean and rich. It is mean to do this as the car's ECU is constantly changing the oxy voltage. However when I'm pushing it, that's when it will indicate the right volume. At 80% throttle position, that's what the manual said anyway haha

Something about the ECU being closed loop and is running the factory programed map.

It does hook up to the oxygen sensor and also if the AF ratio meter is playing up, it could be the oxygen sensor at fault and not the meter. There are 2 types of oxygen sensors and they do get wear out over time apprantely.

Hope this help a bit

Cheers

[blind_elk]

Originally posted by skylineakt

...It is mean to do this as the car's ECU is constantly changing the oxy voltage....

The ECU doesn't (directly) change the O2 sensor voltage at all. The O2 sensor actually produces its own voltage, which varies according to the amount of oxygen in the exhaust gas.

In response to the O2 sensor voltage, the ECU adjusts the fuelling to get the O2 sensor to output a voltage closer to 0.5V, which indicates stoichiometric running. The voltage coming out of the O2 sensor changes very rapidly around the stoichiometric point. Because its is an 'after the fact' adjustment, the ECU will generally overshoot the adjustment, and then needs to adjust the fuelling in the opposite direction.

So the O2 sensor, and thus the gauge, fluctuates between rich and lean.

[skylineakt]

yeah that's what I mean blink haha

The ecu changing the A/F mixture constantly, that's why the reading from the o2 sensor (voltage) is changing too..