Defi D a/f reading?
I have the same guage and my car is tuned for 11.5-11.1 afr on 93 oct at WOT. That is the numbers that you should shoot for but I would compair the gauge to a Wide band to see how accurate. My first one wasn't very accurate so I have a second on the way.
Also during testing of my first guage it seemed to work better when it was grounded by its self on its own spot. The first gound I used was the same ground that my headunit was using and it did some really funky stuff, for example the needle on the gauge wouldn't reach all the way down to 17.0 it would stop at 16.5 and it would peg its self at 10.0 anytime I hit the throttle but when I changed the ground wire it stopped that kind of behavior so just a fyi is you are having similar issues.



