Thread: Tuning for Gas Mileage

If you want to disable O2 sensor feedback, change E038 from F1 to D1. To keep TP from using the WOT (far right) column of the fuel map based on throttle position, change E039 from 3A to 2A.

Dave

Nice my XDF does not have E039. I like how for E038 Calum says not to touch that.

Is messing with E038 - Feedback Control Flags better then just touching E3D0 - O2 Feedback Control, to kill the O2 sensor readings?

You can add E039 by clicking on E038, right click, insert copy of XDF item, then edit the copy and change the name and address.

E3D0 is a timer limit that won't affect AFR. Changing E038 to D1 will disable the O2 sensor analysis and therefore closed loop AFR control.

Dave

I probably will just add it to my XDF. What would the E039 be called?

Interestingly enough, that was the case at first. Calum posted a locked o2 map for people to tune without engine self learning. E3D0 went from FA to F8, but when I was driving it still self learned.

In the comments of for that XDF Item I saw Calum mention using 00 if you would like feedback to be disabled. That did the trick, my A/F ratios were following the map and not self learning.

I call it "Enable Flags".



E3D0 is a timer limit. I'm still working on the B14 code and haven't gotten far enough to tell you exactly what it does, however it is self learn related.



What XDF item?

Dave

The E3D0 - O2 Feedback control deal

I did a little research and E3D0 is a timer limit for a timer that measures how long it has been since the last time the closed loop fuel factor was reduced because the AFR was rich. If the timer expires (E3D0 = 0xFA = 250 => 25secs), the closed loop system is reset and starts over from the beginning. In other words, if its been more than 25 seconds since the O2 sensor detected the AFR was above the rich limit, the closed loop fuel factor is reset to the default value (100). If E3D0 is set to 0, the timer is always expired, the closed loop fuel factor is always reset to 100, so no closed loop adjustment is performed.

This not the way to disable closed loop, as there are some conditions where the timer isn't checked to see if it expired. The way to disable closed loop feedback is with E038.

Dave

So if E038 = D1 are both O2 and Knock disabled?

If it disables the Knock Sensor, I would like to avoid it

F1 => both enabled
D1 => O2 disabled
E1 => knock disabled
C1 => both disabled

Dave