I have a AEM wideband o2 sensor and gauge. The gauge appears to measure correctly, but the ems reads between 5 and 8 AFR. Any ideas? Thanks in advance. I uploaded the file to a dumping site. Scroll to the bottom the site. Downoad the file and open the log file

link to log file


Here is the image. Sorry about the low res pic but it is limited to the netbooks resolution.



Josh

 

I have no idea how the AEM EMS work.. but is there something like a AFR multiplier parameter?

I have an Innovate LC-1 wideband controler and the multiplier was not well configured when I got it, therefore I got AFR's on the 5-6 range.. After changing the AFR multiplier to 14.7 the AFRs were right again..

Are you able to output lambda's instead of AFRs with the EMS? (if the lambdas are ok, then it's a problem of the multiplier)

 

I would guess that you are providing power and / or ground from a poor location, and are getting a voltage offset. You can either fix that, or there may be a voltage offset setting in the EMS.

 

did you follow the setup instructions for the UEGO? are you on the right fuel type setting? Did you calibrate the EMS to read 2.3V when the O2 sensor is disconnected from the UEGO cable by the exhaust pipe?

The answer to one of those question is yes. you need to follow instructions. good luck

 

on gerby's note, you also need to be pulling voltage straight from the battery. if you are not then the voltage offset needed to bring back with UEGO to proper calibration will change as equipment is turned off and on.

K type thermocouples are also very sensitivity to receiving non-battery voltage.

 

I used a multimeter to determine what the voltage of the gauge said to what the ems was saying. And it matched the voltage of the ems with this gain setting, but I did it with the sensor plugged in. What would be a reasonable setting for the gain? Is this the offset you were speaking of?

 

the voltage reading would be spiked at 5v the entire time. It isn't supposed to be like that would it?

 

if its reading 6-8 the afr units are setup for methanol.

goto, configure, then units

go through the drop down to find AFR, change it to afr gasoline.

 

Already set for afr gas. Pretty sure I need to just send the ground wire to the ems. What wire should I be grounding the o2 sensor to?

 

What does it say for o2 volts with the o2 sensor unhooked from the gauge