Does anyone have a formula they use in Evoscan? I have my analog out spliced into the rear o2 sensor. The formula I have now seems to read around 13.8 when the gauge reads 14.7.

 

What formula are you using? Try (x*9/923)+10

If it doesn't work use only "x" and make a table relating the logged values with the values shown in the gauge. For example, 480 for 14.7 AFR. You can do it with engine off, so the reading would be stable.

 

I'll give that a shot, the one I was using now is 10+(20-10)*x/255. If you don't mind me asking, what should I use for response bytes and scaling factor?

 

Sorry, that formula should work only for 2 byte addresses. What is your ROM ID?

 

I should be able to change the response bytes in edit data items right? And I'm 52680017. Thanks your help on this, I really appreciate it.

 

Yes, you can change, but I believe it will give you wrong results.

Your formula should work, perhaps with some offset value. Log only X in Evoscan, 1 byte, with engine off but ACC on. Let your engine idle for a few minutes before you start the log, wait until everything is warmed up. When you turn off the engine, your AFR gauge should be reading something around 14.7, then it will lean a bit. Everytime the gauge changes, check the variation in X logs. Post it here when you finish.

Exemple:

14.7 = 120
14.9 = 125
15 = 127
15.1 = 130

 

Excellent, I'll give that a show this weekend and see what I can come up with. Thanks for your help with this