o2 readings over 2?

[xdxoxuxgx]

During normal driving the o2 readings from the datalogger will fluctuate between 1.00 and 2.00 and above. This would suggest a very rich condition but the reading from the wideband o2 will stay between 12 and 13 most of the time during cruising. The same thing happens at idle where the o2 readings from the datalogger are above 2.00 and the wideband is reading around the mid 14's. Any help would be greatly appreciated.

 

[steve]

Are you sure your looking at the right sensor? On MMCD the one and only 1G O2 sensor is O2-R.

 

[xdxoxuxgx]

i didnt use the mmcd program. i have been using the dsmlogger program which only gives one o2 reading also. would that be the wrong o2?

 

[steve]

Don't know but since the O2 sensor doesn't output more than 1v it's suspect. I have also seen ECU damage that caused problem with the O2 sensor input.

 

[xdxoxuxgx]

we figured it was something with the o2 but then i tried another sensor and it still read the same high numbers. so you think its something with the ecu?

 

[steve]

My first thought is that your datalogger was incorrect but if your using the Pocketlogger or TMO software that isn't the case, The next likely case is a bad ECU followed by the possibility of damaged wiring.

 

[xdxoxuxgx]

ok thanks for the ideas. ill see if any of those are the case.

 

[xdxoxuxgx]

well i opened up the ecu and checked it out and it didnt look like there was any visual damage there. what would i look for in the wiring? i looked at the first few feet of wiring coming right out of the ecu and it looked to be ok. im stumped, please help!!! haha.

 

[steve]

Disconnect the pin for the O2 sensor from the ECU harness using the method in the tech article http://www.dsmtuners.com/forums/art...w-remove-replace-pins-harness-connectors.html and then try logging.

If the voltage is > 0v you have an ECU problem. On the ones I've fixed there was no visible signs of damage it just was.

If it reads 0v with the pin disconnected the try measuring the voltage at the pin before plugging it back in. Work back from there as needed.

 

[xdxoxuxgx]

took the pin and the logger still ran a reading of 2.50v and 100% o2 trim. looking for a new ecu as this is being written. thanks.

 

[xdxoxuxgx]

so i got the new ecu and put that in and still got the crazy readings. turns out it was something with the cam angle sensor.

 

[steve]

Interesting. I don't know how any of the CAS signals would have an impact on the O2 readings but who knows. (other than the pins being 4 in from either end and could be confused if you forget how the pins are numbered and flipped the connector over.)

 

[xdxoxuxgx]

well my friend jumped to conclusions and the cas didn't totally fix it. the afr's are still crazy. sometimes well have to add 30% correction to get afr's around the 13-14 range and sometime we dont have to add any correction. i am totally stumped at this point. when doing some full throttle pulls its still getting 43 counts of knock without pulling timing with the afr's between 10-11 which i heard could be due to the rich conditions.