running rich outta no where, o2 reads .03v

[97ebaygst]

I had a problem pop up outta no where that i can't seem to figure out. The car has been driving fine until a few days ago. It started to run rich so I did a log with evoscan and my o2 sensor was logging .1 volts which means lean if I'm right and its not cycling. When the car is not running the volts read above 1v with the highest Ive seen being 4.5v.

I've even unplugged the sensor and logged a reading of like .039v. Can anyone give me any advice on where i should look.

 

[Dsmkauai]

Is this a narrow or wideband sensor? Sounds like your sensor took a crap bro.

 

[97ebaygst]

Well I have an aem wideband which is what tipped me off but should it still read super rich when the sensors unpluged?

 

[Dsmkauai]

Ya probably not good it's reading when unplugged. I would check all wires good make sure nothing is out of order, check ground wires good. Aem are good for the most part but all o2 sensors fail at some point. When mine failed it was all over the place reading wise, I run the mtx-l with standard Bosch 5 wire sensor. Is there a way to recalibrate the aem units like the mtx-l.?

 

[97ebaygst]

You miss understand my aem reads fine. It was reading rich. My front o2 sensor is what reads lean but my aem wideband picks it up as rich. So my front o2 thinks its lean so it enriches the mixture to the point its constantly running rich. I'm trying to find out if its the sensor or something else because of it doing the same when I unplug it.

 

[Dsmkauai]

Oh ok gotcha sounds like the front o2 is toast bro only other place to suspect would be the ecu or a ground somewhere.