Oxygen Sensor Curiosity

[cxx]

I thought the O2 sensor of my 90 Laser RS Turbo was broken. I tested another one yesterday, the result was the same. The sensor voltages of both sensors are only 0,02 to 0,04 Volts. I have no idea, what's wrong - I don't think, that I own 2 bad oxygen sensors.

 

[DSMeclipse4G63]

when did you take the measurements...and where in the circuit....if thats the signal return voltage on a running car then your running absolute lean(thats if the sensor reads that voltage of course). explain what conditions were happening where your reading the voltage and so on, so I can help you a little better.
Andrew

 

[psychlow]

If that was with it in the car with the car idling, you likely have a short or a break in the wiring to the ECU.

 

[cxx]

I was on my way home, when the Check Engine light came on. I connected my Datalogger and the O2 sensor error code was saved. I looked at the voltage of the O2 sensor and it said something from 0,02 up to 0,04 Volts. Next day, I tried another O2 sensor with the same result: 0,02 up to 0,04 Volts.

After that, I gauged the O2 sensor directly: the result is more or less the same. It also doesn't matter whether the engine is warm or not.

 

[DSMeclipse4G63]

well if you giot the same result with a known good O2 sensor, then its a wiring problem...or a problem with your ecm(ecu as most people refer to it as).
Andrew

 

[flytalon93]

Did you reset the ECU when you replaced with the known good O2?

 

[shoguntalon]

what will happen if you drive your car with only one sensor and you are missing the back one?

 

[psychlow]

The only negative effect to a missing rear O2 sensor is a check engine light. The ECU doesn't use it for any tuning purposes, it's only there to make sure the cat is present and functioning.

 

[cxx]

Thanks so far...

No, I've not yet resetted the ECU. I'll do this today.

@shoguntalon:

My 90 Laser RS Turbo has only one O2 sensor. Are there any 1G DSMs with two O2 sensors?

 

[psychlow]

No.

All 1G DSMs are OBD-I, only requiring 1 O2 sensor.

2G DSMs are OBD-II (not sure if 95's may be OBD-I, someone confirm or deny). OBD-II requires the cat-check secondary O2 sensor.

 

[DSMeclipse4G63]

No.

All 1G DSMs are OBD-I, only requiring 1 O2 sensor.

2G DSMs are OBD-II (not sure if 95's may be OBD-I, someone confirm or deny). OBD-II requires the cat-check secondary O2 sensor.

All 2g dsms are OBD2 chrysler is at the head of the game in diagnostics and OBD stuff, so every DSM from 95 on is obd2. Ive had o2 problems with both front and rear, rear only checks catalyst effeciency and when it stores a code it wont effect drivability, but when my front o2 sensor circuit fouled up it pulled fuel trim codes as well and DEFINATLY messed up my drivability(15.6@100mph).I dont neccesarily think reseting the ecu will help..but I would def. recomend it cause its VERY easy and takes about 10 mins.
Andrew