I made my own air fuel gauge, but ive run into a problem. I assumed that the o2 output was a constant 0-1v supply, but it appears to only periodically check it at idle, at wot its constant, but other than that ot goes to zero, thn about .8v, then zero again. annoying. any help?

 

NOBODY here has made their own A/F gauge????? come on!

 

i haven't but i am interested in knowing how its done or is there already a thread?

 

A normal O2 sensor has a pretty non-linear response. Or more like it's operating range is pretty narrow. The ECU usually can't hold it steady. So when it's working correctly, the sensor is constantly bouncing back & forth between rich & lean.

A sensor often goes bad by getting sluggish. So the ECU looks at the frequency of those high/low swings to decide whether the O2 sensor is healthy (& sets P0133 if it's too slow). Maybe you can try some kind of low-pass filtering at 1 Hz or something like that?? But don't let your filter influence the signal going to the ECU.

 

hmmm, i like how you think... that might work

 

any idea on what size cap I should run in series? 220uF maybe?

 

got it workin