Thread: aem uego not in sync with aem ems. need some help

this is what i have


AEM Wideband O2 UEGO Gauge - Monitor Air/Fuel Ratio with the Digital 30-4100 - Wideband O2 UEGO, Water/Methanol, Stand Alone Engine Management, Piggyback F/IC, Tru Boost Controller, Gauges, Automotive Performance Electronics

yeah, it should work fine. You need to use the 0-5v output from the gauge to run to the ems if your not already doing so.

yeah how i have my aem uego wired up is

red-ignition
black- grounded straight to the hole under the ems straight to the chassis
white-wired to the ems o2 sensor wire

The only other time i couldnt get them to match properly was when the o2 sensor itself was going out. When that happened, I could not get the ems to see what the gauge was even though it was slow responding and so on.

I dont know how old the sensor is but if its old this might be whats happening. Ill pull up my settings for you and get back with you

Also make sure the value for o2 is set to gasoline as well. Just in case its set to something else.

Yeah, mine is set to AEM guage in the wizard and a gain of 1.01

No reason yours shouldnt be different being your using the same aem uego wideband as I am. Again as long as the sensor is good. It should read pretty spot on from what the gauge is seeing to what the aem is seeing. If not and all your settings are right, there is a good possibility that the sensor may be slowing or going out. Thats the only time ive seen that happen. Once I put a brand new sensor on, it was reading spot on matching at all times.

what about the o2 feedback pro gain and int gain..could those gain settings effect the readings?

i unplugged the sesnor and the gauge is reading 14.7 then i adjusted the gain setting to get 14.7 on the ems and the gain is set to 1.00 and both are matching. but it still seems they are off that is why i am wondering if the o2 feedback might be messing with the readings?

no, it could just be lag between what your seeing on the gauge and the ems or again the sensor might be slowing causing the problem. Thats exactly what happened with my old sensor.

check your sensor with a rag and brake cleaner... if you ever used leaded gas your sensor maybe going bad

1)View the ALL Parameters window and watch o2#1 volts
2)Unplug the wideband sensor
3)Check the o2 wire with a multimeter (DC Voltage) coming out of the UEGO. This voltage is the actual o2 voltage at stoich and takes into account any voltage drop across the circuit.
4)Open the o2#1 gain parameter and adjust the gain so that the 02 voltage in parameters matches the o2 voltage you read previously on the multimeter.

These steps just setup your gain properly. ONLY DO THIS IF THE CALIBRATION WIZARD IS NOT WORKING.

If you can shorten your ground wire that would also be better. Ground it under the dash by the fuse block on a good clean grounding point or run back to the battery ground. Sometimes that ECU bracket ground just doesn't work well. Almost all of the issues i have seen when the gauge doesn't match the ems reading is due to bad grounds.

If these two things don't do it, you have a bad sensor.

Brent