I installed a Autometer o2 gauge last month before I left for Taiwan. In the few days I drove it I noticed something strange.

After a 10 minute warm up drive, the first 2 or 3 WOT runs the gauge would show 1 or 2 lights in being rich, about 12.5ish. Indicating that the fuel mixture was at least close. I know it's not an acurate indication, but good as an idiot light.

But after that, each run would get leaner and leaner, untill the gauge would show full lean. I'm running 18psi chips, but even after I turned the boost down to 15psi the gauge results were the same. There is no pinging that I can hear.

I know that o2 sensors are effected by temperature, and the voltage output shows this. But I've never heard of it being this extream before. A fellow Rennlister sent me a link to this which show the relationship of voltage to temp. http://www.halmeter.com/Halmeter.img...0_Brochure.pdf

What do you guys think?

Is the the sign of a o2 sensor going bad?

Thanks again,
Jason

 

Regarding your problem, i heard the good indication from the autometer gauge should be one or two lights in rich when WOT (after 2/3 runs to heat the O² sensor up). Can someone confirm this ?

How should it behave when the motor and O² sensors are in temperature and at idle ?
Here is how mine behaves : 500 kb MPEG file (the oil temp is disconnected)

 

More questions on this
Mine goes to 2 in the green in 5th, and is richer in the lower gears.
It idles at a dim last lean LED.
Partial throttle makes it go up and down though...
Whats mine doing?

 

The O2 Sensor has to hit 600 degrees F before the readings are accurate.
I'll add, after letting off on WOT, the car goes lean (to the last red bar), and stays there on my autometer gauge, until I give gas. What's up?

 

Cyrus,
After letting off of WOT it will be full lean, thats normal.

When an o2 sensor is cold does it read high or low?

 

It fluctuates, in the stoich bars.

 

In case anyone is interested - My 5 wire is ready before my lambda, and I get around 12:1 AFR at idle before the Motronic goes into closed loop and bounces it up to 16.

 

mine dithers between full lean and the 1st green bar when closed loop, 3 greens at WFO
and it will go off when I let off the throttle. ( the DME shuts off fuel on decel ...its normal)