O2 sensor

[thhodges]

Have a question for the master mechinics.

I have lost another O2 sensor. When they are cold they seem to work for just a few minutes. I am using them with a air/fuel mixture meter. also check with degital DVM.

when I first startup I get what appears to be normal reading going from lean (reds) to rich (green's), then back to normal yellows, but after a few minutes at idle it drops to low reds , then no lights. DVM shows .000 volts.
At this point I can richen up the fuel and no change in output of O2, but if I lean mixture a little I start getting a reading app .15 on dvm and first two red led on A/F meter.??

if I shudown the motor for a few minutes and let it cool down.
motor temp is above 150 deg F. when I turn the car on. I get a reading of about .5 to .7 out of the sensor before I start the motor?? is this normal??


What could be fraying my O2 sensors?? Bad gas??

[animal]

Do you have a wideband o2 sensor?

If not then the general consensus is that your a/f guage is really nothing more than a light show. The regular O2 sensors have been shown to be way out of range as far as showing some useful a/f info goes and the gauge only reads as good as the sensor

There is a digital readout wideband O2 setup on the net somewhere for about $800 I believe. They utilize a honda 5 wire 02 sensor and have all the computer stuff to get the readings you want from them.

Granted this does not fix your problem either. You're not losing coolant are you? I've heard that water/vapor can kill O2 sensors pretty quick.

[thhodges]

Thanks for the info.

I do not know if the first two sensors were wide band or not. the first one came with the Edlerbrok tuning set up kit. It was a 3 wire(heater) sensor. The second one I pickup at the locak Autoparts and have no Idia what type it was. It had the same three wire connector at the origanl. Yesterday I got one for a 88 Mustang 5.0, it also is a three wire setup. I rewired it with a correct connector at the O2 end. Now this one for now seems to be working correctly.

The BIG test will be when I connect the O2 output to my SDS ECU and enable closed loop. Then will will see how close i get to passing emmision.

[animal]

I know you can get a recalibrated o2 sensor and gauge that works much better than the standard ones as far as accuracy goes. They are around 2-300 bux I think... but they are still not as accurate as a real wideband setup like those used at a dyno testing facility. If you do got a wideband... I'm jealous :D

[thhodges]

After getting the new O2 sensor and doing some fine tuning and then turning on the closed look on my ECU unit. Iwent back for emmision testing. and it actualy passed this time. Finnaly that is done and I should not have to worry about it again. Need to celerbrate now.
:beer:

[animal]

What better way to celebrate than with a nice smooth off-road pipe :D That is assuming you have hobbyist plates and don't have to worry about that crap anymore.

[JSlimJeff]

I have an autometer afr gauge. I also see that they are not as accurate as you wish. When I originally installed it . at WOT I was at the high end of stoich and now it is at the low limit. I know I am not running lean since I have a wideband plot from the dyno...