unvmys2k

So, I just got my car tuned on AEM EMS Series 2 and we couldn't get the O2 feedback working properly. Car is tuned otherwise, but we all know that temperature can affect the tune (especially on a day like today where it was 31 this morning and high of 64). Therefore, O2 feedback is helpful and important. I purchased the new X series wideband and wired it up as stated for analog feedback (+ to Pin C16, - to Pin D9). The gauge is matching dead on with the data from the EMS. A/F reading is matching 100%. This confirms the EMS is receiving the correct data and that wiring is correct. However, when O2 feedback is turned on the EMS goes ballistic and dumps fuel in. Closed loop feedback turned on and it goes completely nuts. No matter what value you have set, it goes crazy. Being a new X Series, is there something different we should be doing? Car runs great on open loop, but I have to be careful and pay attention to the gauge (not that I wouldn't otherwise). I sent an email to AEM already, but figured I would post in here too. Maybe someone has had this issue before. Details of the car are below.

2000 Honda S2000
AEM EMS Series 2
ID 1000cc Injectors
Hondata 4bar MAP
AEM X Series wideband wired up as primary O2 (replaced OEM primary O2 sensor in header)
Vortech Supercharger with 3.8” pulley

Thanks in advance for any help someone might have.

tunermt

Post the map and a log

tunermt

If the o2 data in Aem tuner matches the gauge display the wiring should be correct and its more than likely something in the calibration.

If it's hard to post the cal file feel free to email me

markforrester99

Screenshot the feedback part of the calibration.

You need to make sure that you use negative numbers in the lean adjustment setting otherwise it will keep adding fuel when it wants to be leaning it off.

When i get home i will take a screenshot of my calibration and you can have a look

unvmys2k

Thanks for the replies guys. I haven't been on here much since my S2K is being prepped for paint. I haven't driven in over a month. I can post a screen shot of my current settings. Is there a way to post my CAL file on here? I also have a video of what happens when I turn the O2 feedback on/off.

unvmys2k

Here is a snapshot of my O2 Feedback tab

unvmys2k

unvmys2k

Any suggestions guys?

markforrester99

Hi Mate,

Sorry i completely missed your reply. Your O2 settings are wrong on part of the calibration. Your ecu is set to only respond to the fuel mixture every second. Most widebands now have a response time of around 50 miliseconds. I have attached my config.

Also you have set the O2 feedback to work when in boost which is fine if you know your sensor is okay but can cause issues if the sensor fails and the ecu starts to pull fuel out of the map at high boost.

markforrester99

Also O2 feedback isn't great around idle with larger injectors. The main reason is that it will sometimes yoyo the mixture up and down. In my case it takes the injectors below their min opening time and the idle becomes really lumpy. I can only get it steady around 1150rpm and 14 AFR